Question

Which of the given expressions results in 0 when evaluated at x = 5? A. 5x(x − 7) B. (x − 8)(x − 5) C. (x + 7)(x − 2) D. (x + 5)(x − 8)

Answer 1

The answer is B. My reasoning is because x is equal to 5 and the expression in the first set of parenthesis equals (-3) and the expression in the second set of parenthesis equals (0). Now when you get those expressions simplified, you multiply them together. Making it equal to 0. I hope this helps you understand. Use PEMDAS if you can recall what that is from school.

Answer 2

B. (x - 8)(x - 5)

Explanation:

If you plugged in x = 5 into the 2nd equation, you would see that you would be multiplying by 0, which would turn everything zero.