(2x-9)(x+1)=(x-3)(x+3)

3 min read Jun 16, 2024
(2x-9)(x+1)=(x-3)(x+3)

Solving the Equation: (2x-9)(x+1)=(x-3)(x+3)

This equation involves expanding brackets and simplifying to find the solution for x. Let's break down the steps:

1. Expand the Brackets

First, we expand the brackets on both sides of the equation using the FOIL method (First, Outer, Inner, Last):

  • Left side: (2x-9)(x+1) = 2x² + 2x - 9x - 9
  • Right side: (x-3)(x+3) = x² - 9 (This is a special case of the difference of squares)

Now the equation becomes: 2x² - 7x - 9 = x² - 9

2. Simplify and Solve for x

To solve for x, we need to rearrange the equation so that all terms are on one side:

  • Subtract x² from both sides: x² - 7x - 9 = -9
  • Add 9 to both sides: x² - 7x = 0

Now we have a quadratic equation. We can solve it by factoring:

  • Factor out x: x(x - 7) = 0

For the product of two terms to be zero, at least one of the terms must be zero. Therefore, we have two possible solutions:

  • x = 0
  • x - 7 = 0 => x = 7

3. Verification

To ensure our solutions are correct, we can substitute them back into the original equation:

  • For x = 0: (2(0)-9)(0+1) = (0-3)(0+3) => -9 = -9 (This holds true)
  • For x = 7: (2(7)-9)(7+1) = (7-3)(7+3) => 56 = 56 (This holds true)

Therefore, the solutions to the equation (2x-9)(x+1)=(x-3)(x+3) are x = 0 and x = 7.