Question

Помогите разложить на множители 
1) 25-y^2
2) 16a^2
3) -8ab+b^2

Answer 1

$25-y^2=5^2-y^2=(5-y)(5+y)$
$16a^2=(4a)^2$
$16a^2-8ab+b^2=(4a)^2-2*4a*b+b^2=(4a-b)^2$
$-8ab+b^2=b(-8a+b)=(b-8a)b$