Question

When 9x2 - 100 is factored, it is equivalent to (3x - b)(3x + b).
What is a value for b?
(1) 50 (3) 3
(2) 10 (4) 100

Answer 1

(9 x 2 = 18) (18-100=-82) So you have to be able to multiply 3x - b and 3x + b to get -82. I believe the answer is (2).10