Simplify The Expression: (a^2b^-3 / A^-2b^2)^2

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Let's dive into simplifying this algebraic expression! This article will guide you step-by-step through the process of simplifying the expression (a2b−3a−2b2)2(\frac{a^2 b^{-3}}{a^{-2} b^2})^2, where aa and bb are not equal to zero. We'll break down the key concepts and rules of exponents, making it easy to understand each step. By the end, you'll not only have the simplified expression but also a solid understanding of how to tackle similar problems. So, let's get started and master the art of simplifying algebraic expressions!

Understanding the Basics: Exponent Rules

Before we jump into the main expression, it's crucial to have a firm grasp of the exponent rules we'll be using. These rules are the foundation for simplifying expressions involving powers. Let's take a closer look at some of the most important rules:

  1. Product of Powers Rule: When multiplying powers with the same base, you add the exponents. Mathematically, this is represented as xmimesxn=xm+nx^m imes x^n = x^{m+n}. For example, if you have a2imesa3a^2 imes a^3, you would add the exponents (2 and 3) to get a5a^5. This rule is fundamental in simplifying expressions where you see the same base raised to different powers being multiplied together.

  2. Quotient of Powers Rule: When dividing powers with the same base, you subtract the exponents. This rule is expressed as xmxn=xm−n\frac{x^m}{x^n} = x^{m-n}. Consider the expression b5b2\frac{b^5}{b^2}. To simplify this, you would subtract the exponents (5 and 2) to obtain b3b^3. This rule is essential when dealing with fractions where the numerator and denominator have the same base raised to different powers.

  3. Power of a Power Rule: When raising a power to another power, you multiply the exponents. This rule is represented as (xm)n=xmimesn(x^m)^n = x^{m imes n}. For instance, if you have (c3)4(c^3)^4, you would multiply the exponents (3 and 4) to get c12c^{12}. This rule is particularly useful when simplifying expressions that involve exponents raised to further powers.

  4. Power of a Product Rule: When raising a product to a power, you distribute the power to each factor within the parentheses. This is mathematically written as (xy)n=xnyn(xy)^n = x^n y^n. Imagine you have the expression (2a)3(2a)^3. Applying this rule, you would distribute the power of 3 to both 2 and a, resulting in 23a32^3 a^3, which simplifies to 8a38a^3. This rule helps in simplifying expressions where a product of terms is raised to a power.

  5. Power of a Quotient Rule: When raising a quotient to a power, you distribute the power to both the numerator and the denominator. This rule can be expressed as (xy)n=xnyn(\frac{x}{y})^n = \frac{x^n}{y^n}. For example, if you have (ab)4(\frac{a}{b})^4, you would distribute the power of 4 to both a and b, resulting in a4b4\frac{a^4}{b^4}. This rule is vital when simplifying expressions involving fractions raised to a power.

  6. Negative Exponent Rule: A term raised to a negative exponent is equal to the reciprocal of the term raised to the positive exponent. This is represented as x−n=1xnx^{-n} = \frac{1}{x^n}. For instance, a−2a^{-2} is equivalent to 1a2\frac{1}{a^2}. This rule is crucial for dealing with negative exponents and converting them into positive exponents for easier simplification.

  7. Zero Exponent Rule: Any non-zero term raised to the power of zero is equal to 1. This is mathematically written as x0=1x^0 = 1 (where x ≠ 0). For example, 505^0 equals 1. This rule is a fundamental concept in simplifying expressions and often appears in various mathematical contexts.

Understanding and applying these exponent rules correctly is the key to simplifying complex expressions. Make sure you have a solid understanding of each rule before moving on to the next section. Remember, practice makes perfect, so try working through various examples to reinforce your understanding. With a good grasp of these rules, you'll be well-equipped to tackle the expression we're going to simplify.

Step-by-Step Simplification

Now that we have reviewed the exponent rules, let's simplify the expression (a2b−3a−2b2)2(\frac{a^2 b^{-3}}{a^{-2} b^2})^2 step-by-step. This process will demonstrate how these rules are applied in practice. We will break it down into manageable parts to make it easier to follow.

Step 1: Apply the Power of a Quotient Rule

The first step in simplifying the expression is to apply the power of a quotient rule. This rule states that (xy)n=xnyn(\frac{x}{y})^n = \frac{x^n}{y^n}. Applying this rule to our expression, we distribute the exponent 2 to both the numerator and the denominator:

(a2b−3a−2b2)2=(a2b−3)2(a−2b2)2(\frac{a^2 b^{-3}}{a^{-2} b^2})^2 = \frac{(a^2 b^{-3})^2}{(a^{-2} b^2)^2}

This step helps us to separate the terms in the numerator and the denominator, making it easier to apply further rules.

Step 2: Apply the Power of a Product Rule

Next, we apply the power of a product rule, which states that (xy)n=xnyn(xy)^n = x^n y^n. We apply this rule to both the numerator and the denominator:

(a2b−3)2(a−2b2)2=a2imes2b−3imes2a−2imes2b2imes2=a4b−6a−4b4\frac{(a^2 b^{-3})^2}{(a^{-2} b^2)^2} = \frac{a^{2 imes 2} b^{-3 imes 2}}{a^{-2 imes 2} b^{2 imes 2}} = \frac{a^4 b^{-6}}{a^{-4} b^4}

Here, we multiplied the exponents inside the parentheses by the outer exponent. This step simplifies the expression further by removing the parentheses.

Step 3: Apply the Quotient of Powers Rule

Now, we apply the quotient of powers rule, which states that xmxn=xm−n\frac{x^m}{x^n} = x^{m-n}. We apply this rule separately to the terms with the base a and the terms with the base b:

a4b−6a−4b4=a4−(−4)b−6−4=a4+4b−10=a8b−10\frac{a^4 b^{-6}}{a^{-4} b^4} = a^{4 - (-4)} b^{-6 - 4} = a^{4 + 4} b^{-10} = a^8 b^{-10}

In this step, we subtracted the exponents of like bases. This simplifies the expression further and combines the terms with the same base.

Step 4: Apply the Negative Exponent Rule

Finally, we apply the negative exponent rule, which states that x−n=1xnx^{-n} = \frac{1}{x^n}. We apply this rule to the term b−10b^{-10}:

a8b−10=a8×1b10=a8b10a^8 b^{-10} = a^8 \times \frac{1}{b^{10}} = \frac{a^8}{b^{10}}

This step removes the negative exponent, giving us the final simplified expression. By converting the negative exponent to a positive exponent, we express the term in its simplest form.

Final Simplified Expression

Therefore, the simplified form of the expression (a2b−3a−2b2)2(\frac{a^2 b^{-3}}{a^{-2} b^2})^2 is a8b10\frac{a^8}{b^{10}}. Each step we took was crucial in reaching this simplified form, and understanding the exponent rules made the process straightforward.

Common Mistakes to Avoid

When simplifying expressions with exponents, it's easy to make mistakes if you're not careful. Here are some common pitfalls to watch out for:

  1. Incorrectly Applying the Product of Powers Rule: A common mistake is to multiply the bases instead of adding the exponents when using the product of powers rule. Remember, xmimesxn=xm+nx^m imes x^n = x^{m+n}, not xmimesxn=(ximesx)m+nx^m imes x^n = (x imes x)^{m+n}. For example, 22imes232^2 imes 2^3 is 22+3=25=322^{2+3} = 2^5 = 32, not 454^5.

  2. Incorrectly Applying the Quotient of Powers Rule: Similar to the product rule, a mistake in the quotient rule involves dividing the bases instead of subtracting the exponents. Remember, xmxn=xm−n\frac{x^m}{x^n} = x^{m-n}, not xmxn=(xx)m−n\frac{x^m}{x^n} = (\frac{x}{x})^{m-n}. For example, 3532\frac{3^5}{3^2} is 35−2=33=273^{5-2} = 3^3 = 27, not 131^3.

  3. Forgetting to Distribute the Exponent: When dealing with the power of a product or quotient, it's crucial to distribute the exponent to every factor. For example, (ab)n=anbn(ab)^n = a^n b^n. A common mistake is to only apply the exponent to one factor, like writing (2x)2=2x2(2x)^2 = 2x^2 instead of 22x2=4x22^2 x^2 = 4x^2.

  4. Misunderstanding Negative Exponents: Negative exponents can be tricky. Remember that x−n=1xnx^{-n} = \frac{1}{x^n}. A common error is to treat a negative exponent as making the base negative, rather than taking the reciprocal. For example, 2−32^{-3} is 123=18\frac{1}{2^3} = \frac{1}{8}, not -8.

  5. Ignoring the Order of Operations: Always follow the order of operations (PEMDAS/BODMAS). Exponents should be dealt with before multiplication, division, addition, or subtraction. Forgetting this can lead to incorrect simplifications.

  6. Overcomplicating the Process: Sometimes, students try to simplify everything at once, leading to confusion. Break the expression down into smaller, manageable steps. This makes it easier to keep track of the rules you're applying and reduces the chance of error.

  7. Not Simplifying Completely: Make sure you simplify the expression as much as possible. This includes dealing with negative exponents, combining like terms, and reducing fractions. Leaving the expression partially simplified means you haven't finished the job.

By being mindful of these common mistakes and practicing consistently, you can improve your accuracy and confidence in simplifying expressions with exponents. Always double-check your work and take it one step at a time to avoid these pitfalls.

Practice Problems

To solidify your understanding of simplifying expressions with exponents, let's work through a few more practice problems. These examples will give you a chance to apply the rules we've discussed and build your skills. Remember to take each problem step-by-step and double-check your work. Working through practice problems is one of the most effective ways to learn and retain new mathematical concepts.

Practice Problem 1: Simplify (x3y−2x−1y4)3(\frac{x^3 y^{-2}}{x^{-1} y^4})^3

Solution:

  1. Apply the power of a quotient rule: (x3y−2x−1y4)3=(x3y−2)3(x−1y4)3(\frac{x^3 y^{-2}}{x^{-1} y^4})^3 = \frac{(x^3 y^{-2})^3}{(x^{-1} y^4)^3}
  2. Apply the power of a product rule: (x3y−2)3(x−1y4)3=x3×3y−2×3x−1×3y4×3=x9y−6x−3y12\frac{(x^3 y^{-2})^3}{(x^{-1} y^4)^3} = \frac{x^{3 \times 3} y^{-2 \times 3}}{x^{-1 \times 3} y^{4 \times 3}} = \frac{x^9 y^{-6}}{x^{-3} y^{12}}
  3. Apply the quotient of powers rule: x9y−6x−3y12=x9−(−3)y−6−12=x12y−18\frac{x^9 y^{-6}}{x^{-3} y^{12}} = x^{9 - (-3)} y^{-6 - 12} = x^{12} y^{-18}
  4. Apply the negative exponent rule: x12y−18=x12×1y18=x12y18x^{12} y^{-18} = x^{12} \times \frac{1}{y^{18}} = \frac{x^{12}}{y^{18}}

So, the simplified expression is x12y18\frac{x^{12}}{y^{18}}.

Practice Problem 2: Simplify (2a2b−1)4(3a−3b2)−2(2a^2 b^{-1})^4 (3a^{-3} b^2)^{-2}

Solution:

  1. Apply the power of a product rule to both terms: (2a2b−1)4=24a2×4b−1×4=16a8b−4(2a^2 b^{-1})^4 = 2^4 a^{2 \times 4} b^{-1 \times 4} = 16a^8 b^{-4} and (3a−3b2)−2=3−2a−3×−2b2×−2=3−2a6b−4(3a^{-3} b^2)^{-2} = 3^{-2} a^{-3 \times -2} b^{2 \times -2} = 3^{-2} a^6 b^{-4}
  2. Combine the simplified terms: 16a8b−4×3−2a6b−4=16×132a8a6b−4b−4=169a8a6b−4b−416a^8 b^{-4} \times 3^{-2} a^6 b^{-4} = 16 \times \frac{1}{3^2} a^8 a^6 b^{-4} b^{-4} = \frac{16}{9} a^8 a^6 b^{-4} b^{-4}
  3. Apply the product of powers rule: 169a8a6b−4b−4=169a8+6b−4+(−4)=169a14b−8\frac{16}{9} a^8 a^6 b^{-4} b^{-4} = \frac{16}{9} a^{8 + 6} b^{-4 + (-4)} = \frac{16}{9} a^{14} b^{-8}
  4. Apply the negative exponent rule: 169a14b−8=169a14×1b8=16a149b8\frac{16}{9} a^{14} b^{-8} = \frac{16}{9} a^{14} \times \frac{1}{b^8} = \frac{16a^{14}}{9b^8}

Thus, the simplified expression is 16a149b8\frac{16a^{14}}{9b^8}.

Practice Problem 3: Simplify (4x5y−3)2(2x−2y4)3\frac{(4x^5 y^{-3})^2}{(2x^{-2} y^4)^3}

Solution:

  1. Apply the power of a product rule to both the numerator and the denominator: (4x5y−3)2=42x5×2y−3×2=16x10y−6(4x^5 y^{-3})^2 = 4^2 x^{5 \times 2} y^{-3 \times 2} = 16x^{10} y^{-6} and (2x−2y4)3=23x−2×3y4×3=8x−6y12(2x^{-2} y^4)^3 = 2^3 x^{-2 \times 3} y^{4 \times 3} = 8x^{-6} y^{12}
  2. Rewrite the expression with the simplified terms: 16x10y−68x−6y12\frac{16x^{10} y^{-6}}{8x^{-6} y^{12}}
  3. Simplify the constants: 168=2\frac{16}{8} = 2
  4. Apply the quotient of powers rule: 2×x10x−6×y−6y12=2x10−(−6)y−6−12=2x16y−182 \times \frac{x^{10}}{x^{-6}} \times \frac{y^{-6}}{y^{12}} = 2 x^{10 - (-6)} y^{-6 - 12} = 2 x^{16} y^{-18}
  5. Apply the negative exponent rule: 2x16y−18=2x16×1y18=2x16y182 x^{16} y^{-18} = 2 x^{16} \times \frac{1}{y^{18}} = \frac{2x^{16}}{y^{18}}

Hence, the simplified expression is 2x16y18\frac{2x^{16}}{y^{18}}.

By working through these practice problems, you've had the chance to apply the exponent rules in different contexts. Each problem required a careful, step-by-step approach, highlighting the importance of understanding and correctly applying the rules. Remember, consistent practice is key to mastering these concepts. Try to solve similar problems on your own to further enhance your skills.

Conclusion

In this article, we've explored how to simplify expressions with exponents, focusing on the specific example of (a2b−3a−2b2)2(\frac{a^2 b^{-3}}{a^{-2} b^2})^2. We began by reviewing the fundamental exponent rules, which are the building blocks for simplifying algebraic expressions. We then broke down the simplification process into manageable steps, applying these rules methodically to reach the final answer: a8b10\frac{a^8}{b^{10}}.

We also highlighted common mistakes to avoid, such as incorrectly applying the product or quotient rules, mishandling negative exponents, and not distributing exponents properly. Recognizing these pitfalls is crucial for improving accuracy and avoiding errors. By being mindful of these common mistakes, you can enhance your problem-solving skills and ensure correct simplifications.

Finally, we worked through several practice problems to reinforce the concepts and give you the opportunity to apply what you've learned. These examples demonstrated how to tackle different types of expressions and solidify your understanding of exponent rules. Consistent practice is essential for mastering any mathematical concept, and simplifying expressions with exponents is no exception. The more you practice, the more confident and proficient you'll become.

Simplifying expressions with exponents is a foundational skill in algebra, and mastering it will benefit you in many areas of mathematics. By understanding the rules, avoiding common mistakes, and practicing regularly, you can confidently tackle even the most complex expressions. Remember to approach each problem step-by-step and double-check your work to ensure accuracy. With dedication and practice, you can excel in simplifying algebraic expressions.

For further exploration and practice, you can visit trusted websites like Khan Academy's Exponent Rules Section. Keep practicing, and you'll become a pro at simplifying expressions!