"If possible, completely factor the expression. (If the expression is not factorable, enter NF.) x2 − 6x − 7"

Answer 1

the factors of -7 are
-1 and 7
1 and -7

can you pick them so they add up to -6?

(x+1)(x-7)

Answer 2

(If the expression is nonfactorable over the integers, enter NONFACTORABLE.)
y2 − 5y + 25