Question

1) (x+3)^2 - (x+1)^2

2) (x-4)^2 - 16(x+2)^2

Answer 1

a^2-b^2 = (a-b)(a+b) so

(x+3)^2 - (x+1)^2
= ((x+3)-(x+1))((x+3)+(x+1))
= (2)(2x+4)
= 4x+8

similarly for the other