Question

Which of the following is equivalent to 121 − x2 ?

(11 − x)^2
(11 − x)x
(11 − x)(11 − x)
(11 − x)(11 + x)
(121 + x)(1 − x)

Answer 1

Hint:

\[\large (x + a)(x - a) = x^2 - a^2\]

Answer 2

Also a good way to do this problem, is to expand all of your given solutions, that way it will give you practice for other problems.