Question

спростіть вираз (6x-y)(6x+y)+(x+3y)(3y-x)
(фото)​

Answer 1

Ответ:

$a)\ \ (6x-y)(6x+y)+(x+3y)(3y-x)=\\\\=(6x)^2-y^2+(3y)^2-x^2=36x^2-y^2+9y^2-x^2=35x^2+8y^2\\\\\\b)\ \ (x+7)^2-(x-11)(x+11)=x^2+14x+49-(x^2-121)=\\\\=14x+170$