Question

is x^2-16 even factorable? i had factored it to (x-4)^2. but that doesn't make any sense because -4*-4=16 not -16. and if i had factored it to (x+4)^2 it doesn't work because 4*4=16 still not -16

Answer 1

yes. it is a difference of 2 squares.

\[a^2 - b^2 = (a+b)(a-b)\]

Try expanding (x+4)(x-4) :)