Expanding and Solving the Equation: (3 + 5x)(2 – 3x) = 12 – 15x²
This article will walk through the process of expanding and solving the equation (3 + 5x)(2 – 3x) = 12 – 15x². We will use the FOIL method to expand the left side of the equation and then simplify to find the solution.
Expanding the Left Side
The FOIL method stands for First, Outer, Inner, Last. It's a mnemonic device to help remember how to multiply two binomials:
- First: Multiply the first terms of each binomial: 3 * 2 = 6
- Outer: Multiply the outer terms of the binomials: 3 * -3x = -9x
- Inner: Multiply the inner terms of the binomials: 5x * 2 = 10x
- Last: Multiply the last terms of the binomials: 5x * -3x = -15x²
Therefore, the expanded left side of the equation becomes: 6 - 9x + 10x - 15x²
Simplifying the Equation
Now, let's combine the like terms:
6 - 9x + 10x - 15x² = 12 - 15x²
This simplifies to:
x + 6 = 12
Solving for x
Finally, we can solve for x:
- Subtract 6 from both sides: x = 6
Therefore, the solution to the equation (3 + 5x)(2 – 3x) = 12 – 15x² is x = 6.