X^2-9y^2
a)x^2-9y^2
b)4/25x^2-36y^2
c)(x+5)^2-16
d)49a^2-(3a-b)^2
e)(2x+3)^2-(x-7)^2
f)4(x-y)^2-(3x+y)^2
(ai gửi xong nhanh dc 7 sao nha )^^
b)4/25x^2-36y^2
c)(x+5)^2-16
d)49a^2-(3a-b)^2
e)(2x+3)^2-(x-7)^2
f)4(x-y)^2-(3x+y)^2
(ai gửi xong nhanh dc 7 sao nha )^^