Răspuns :
(3x-y)²-(2x+3y)²
a²-b²=(a-b)(a+b)
la tine a²=3x-y si b=2x+3y
(3x-y-2x-3y)(3x-y+2x+3y)=(x-4y)(5x+2y)
a²-b²=(a-b)(a+b)
la tine a²=3x-y si b=2x+3y
(3x-y-2x-3y)(3x-y+2x+3y)=(x-4y)(5x+2y)