In order to find the correct answer, you'll need to fill in the factors for x for each answer.
A: -7^2 --6-42 is -85, which is not equal to 0.
B: 7^2 -6-42 is 1.
C: -7^2 -6-42 is -97, which is not equal to 0.
D. 7^2 --6-42 is 13, which is not equal to 0.
I'm going to have to say B. x=7, x=6.