(b+4)квадрат-2b(5b+4)

Question

(b+4)квадрат-2b(5b+4)

Answer 1

b^2+8b+16-10b^2-8b=-9b^2+16

Answer 2

(b+4)^2 - 2b(5b+4)=  b^2+8b+16 - 10b^2-8b= 16- 9b^2 = (4-3b) (4+3b)