Question

Разложите на множители
A) 16xy-4y;
B) 25x^6-20x^3y^4+y^8
C) an-7a-bn+7b

Answer 1

$16xy-4y=4y(4x-1)\\25x^6-20x^3y^4+4y^8=(5x^3-2y^4)^2\\an-7a-bn+7b=a(n-7)-b(n-7)=(n-7)(a-b)\\\P.S.; ; 25x^6-20x^3y^4+y^8=(5x^3-2y^4)^2-3y^8=\\=(5x^3-2y^4)^2-(sqrt3y^4)^2=(5x^3-2y^4-sqrt3y^4)(5x^3-2y^4+sqrt3y^4)$