Unlocking Quadratic Equations: A Step-by-Step Guide

by Alex Johnson 52 views

Welcome! Let's dive into the fascinating world of quadratic equations. We'll explore how to solve them through factoring, a fundamental skill in algebra. Factoring is like detective work, breaking down complex expressions into simpler components. This approach lets us find the roots or solutions, which are the values of x that make the equation true. We'll be working through several examples, breaking down each step to make the process clear and easy to follow. Get ready to flex your mathematical muscles and unlock the secrets of quadratic equations! This guide is designed to transform complex problems into manageable steps, making the learning process both effective and enjoyable. Remember, practice is key, so grab a pen and paper, and let's get started. We will start with the first equation which is 16x2βˆ’8x+1=016x^2 - 8x + 1 = 0, then we will move to the second one, which is x2βˆ’xβˆ’30=0x^2 - x - 30 = 0. After that, we'll solve 9x2βˆ’49=09x^2 - 49 = 0 and finally, we'll address the quadratic equation 3x2+17xβˆ’6=03x^2 + 17x - 6 = 0. By the end of this guide, you will be well-equipped to tackle similar problems with confidence.

Solving 16x2βˆ’8x+1=016x^2 - 8x + 1 = 0: Perfect Square Trinomial

Let's begin with the equation 16x2βˆ’8x+1=016x^2 - 8x + 1 = 0. This is a classic example of a perfect square trinomial. Recognizing this pattern is the key to a quick and efficient solution. In a perfect square trinomial, the first and last terms are perfect squares, and the middle term is twice the product of the square roots of the first and last terms. In our equation, the square root of 16x216x^2 is 4x4x, and the square root of 11 is 11. Twice the product of 4x4x and 11 is 8x8x, which matches the middle term (ignoring the negative sign for now, as it indicates a subtraction). So, this equation fits the pattern perfectly. Therefore, we can factor it as (4xβˆ’1)2=0(4x - 1)^2 = 0. To solve for x, we take the square root of both sides, resulting in 4xβˆ’1=04x - 1 = 0. Then, we add 11 to both sides, which gives us 4x=14x = 1. Finally, we divide both sides by 44 to isolate x, giving us x = rac{1}{4}. Thus, the solution to the equation 16x2βˆ’8x+1=016x^2 - 8x + 1 = 0 is x = rac{1}{4}. This means that the quadratic equation has one real root, also known as a repeated root, because the factor (4xβˆ’1)(4x - 1) appears twice. This root represents the point where the parabola (the graph of the quadratic equation) touches the x-axis.

Now, let's break down the steps clearly.

  1. Recognize the Pattern: Identify that 16x2βˆ’8x+116x^2 - 8x + 1 is a perfect square trinomial.
  2. Factor: Factor the expression into (4xβˆ’1)2=0(4x - 1)^2 = 0.
  3. Solve: Set the factor equal to zero: 4xβˆ’1=04x - 1 = 0.
  4. Isolate x: Add 11 to both sides: 4x=14x = 1.
  5. Find x: Divide both sides by 44: x = rac{1}{4}.

So, the solution to the equation is x = rac{1}{4}. Understanding perfect square trinomials allows you to solve this kind of equation quickly and efficiently. Keep in mind this pattern as it often appears in algebra problems.

Solving x2βˆ’xβˆ’30=0x^2 - x - 30 = 0: Factoring Quadratics

Next, let's solve x2βˆ’xβˆ’30=0x^2 - x - 30 = 0. This equation requires a different factoring approach. Here, we're looking for two numbers that multiply to give us the constant term (-30) and add up to the coefficient of the x term (-1). Think of it like this: (x+a)(x+b)=x2+(a+b)x+ab(x + a)(x + b) = x^2 + (a + b)x + ab, where a and b are the two numbers we're looking for. In this case, those two numbers are βˆ’6-6 and 55, because βˆ’6βˆ—5=βˆ’30-6 * 5 = -30 and βˆ’6+5=βˆ’1-6 + 5 = -1. Therefore, we can factor the equation as (xβˆ’6)(x+5)=0(x - 6)(x + 5) = 0. Now, we set each factor equal to zero and solve for x. For the first factor, xβˆ’6=0x - 6 = 0, which gives us x=6x = 6. For the second factor, x+5=0x + 5 = 0, which gives us x=βˆ’5x = -5. So, the solutions to the equation x2βˆ’xβˆ’30=0x^2 - x - 30 = 0 are x=6x = 6 and x=βˆ’5x = -5. These are the two points where the parabola crosses the x-axis. This factoring technique is a cornerstone of algebra, and understanding it will boost your problem-solving skills considerably. It's often helpful to list out the factor pairs of the constant term to help you find the right combination.

Let's outline the steps again.

  1. Find the Numbers: Identify two numbers that multiply to -30 and add up to -1.
  2. Factor: Factor the equation into (xβˆ’6)(x+5)=0(x - 6)(x + 5) = 0.
  3. Solve: Set each factor to zero: xβˆ’6=0x - 6 = 0 and x+5=0x + 5 = 0.
  4. Isolate x: Solve for x: x=6x = 6 and x=βˆ’5x = -5.

Therefore, the solutions are x=6x = 6 and x=βˆ’5x = -5. This method is a standard approach to solving quadratic equations where the leading coefficient is 1. The key lies in finding the correct factor pairs that satisfy both multiplication and addition conditions.

Solving 9x2βˆ’49=09x^2 - 49 = 0: Difference of Squares

Moving on, let's tackle 9x2βˆ’49=09x^2 - 49 = 0. This is an example of a difference of squares. The difference of squares is a special factoring pattern that appears when you have two perfect squares separated by a subtraction sign. In this case, 9x29x^2 is the square of 3x3x, and 4949 is the square of 77. The formula for factoring a difference of squares is a2βˆ’b2=(aβˆ’b)(a+b)a^2 - b^2 = (a - b)(a + b). Applying this to our equation, we get (3xβˆ’7)(3x+7)=0(3x - 7)(3x + 7) = 0. Now, we set each factor equal to zero and solve for x. For the first factor, 3xβˆ’7=03x - 7 = 0, which gives us 3x=73x = 7, and thus x = rac{7}{3}. For the second factor, 3x+7=03x + 7 = 0, which gives us 3x=βˆ’73x = -7, and thus x = - rac{7}{3}. Therefore, the solutions to the equation 9x2βˆ’49=09x^2 - 49 = 0 are x = rac{7}{3} and x = - rac{7}{3}. This is a common pattern to recognize, as it allows for a straightforward factorization. The two solutions are equidistant from zero on the number line, a characteristic of equations that represent symmetrical parabolas.

Here are the steps in detail.

  1. Recognize the Pattern: Identify 9x2βˆ’499x^2 - 49 as a difference of squares.
  2. Factor: Factor the expression into (3xβˆ’7)(3x+7)=0(3x - 7)(3x + 7) = 0.
  3. Solve: Set each factor to zero: 3xβˆ’7=03x - 7 = 0 and 3x+7=03x + 7 = 0.
  4. Isolate x: Solve for x: x = rac{7}{3} and x = - rac{7}{3}.

Thus, the solutions are x = rac{7}{3} and x = - rac{7}{3}. The difference of squares is a powerful factoring technique that simplifies many quadratic equations, making them easier to solve.

Solving 3x2+17xβˆ’6=03x^2 + 17x - 6 = 0: Factoring with a Leading Coefficient

Finally, let's solve 3x2+17xβˆ’6=03x^2 + 17x - 6 = 0. This equation involves factoring a quadratic expression where the leading coefficient (the coefficient of x2x^2) is not equal to 11. This type of factoring requires a slightly different approach. One method is to use the