7. Which of the following expressions is equivalent to 3x^+6x -24 ? A. 3(x+2)(x-4) B. 3(x-2)(x+4) C. (x+6)(x-12) D. (x-6)(x+12)

Step 1 ：The problem is asking for the equivalent expression of the quadratic equation \(3x^2+6x-24\). We can solve this by factoring the quadratic equation. The factored form of a quadratic equation is usually in the form of \((x-a)(x-b)\) where a and b are the roots of the equation. We can find the roots by using the quadratic formula or by factoring.

Step 2 ：The factored expression of the quadratic equation \(3x^2+6x-24\) is \(3(x - 2)(x + 4)\). Comparing this with the options given in the question, it matches with option B.

Step 3 ：So, the correct answer is \(\boxed{B. 3(x-2)(x+4)}\)