Question

(3x-6)(3x+6)-3(2x-4)=?

Answer 1

$\displaystyle \tt (3x-6)(3x+6)-3(2x-4)=(3x)^2-6^2-3\cdot2x-3\cdot(-4)=\\\\ \displaystyle \tt =9x^2-36-6x+12=\bold{9x^2-6x-24}$

Answer 2

Let's simplify the expression step by step:

(3x - 6)(3x + 6) - 3(2x - 4)

First, let's apply the distributive property to both sets of parentheses:

(3x * 3x) + (3x * 6) - (6 * 3x) - (6 * 6) - (3 * 2x) + (3 * 4)

Now, let's perform the multiplications:

9x^2 + 18x - 18x - 36 - 6x + 12

Notice that the terms -18x and 18x cancel each other out, leaving us with:

9x^2 - 6x - 36 + 12

Finally, combine the constant terms:

9x^2 - 6x - 24

So, the simplified expression is:

9x^2 - 6x - 24