(3x+y)²-(x-5y)²

(3x+y)²-(x-5y)²
(3x+y)²-(x-5y)²

(3x+y)²-(x-5y)²
(3x+y)²-(x-5y)²
=(3x+y+x-5y)(3x+y-x+5y)
=(4x-4y)(2x+6y)
=8（x-y）（x+3y）

8(x-y)(x+3y)请采纳

平方差公式
(3x+y)²-(x-5y)²=[(3x+y)+(x-5y)][(3x+y)-(x-5y)]
=(3x+y+x-5y)(3x+y-x+5y)
=(4x-4y)(2x+6y)
=4(x-y)*2(x+3y)
=8(x-y)(x+3y)