Question

Which factor 25^2+40x+16 and 25x^2-16 have in common

Answer 1

25^2+40x+16

= (5x + 4)(5x + 4)

and

25x^2-16

= (5x)^2 -(4)^2

= (5x + 4)(5x - 4)

Both have same factor (5x + 4)