Bài 4:
a: \(A=9-\left(x-y\right)^2\)
\(=\left(3-x+y\right)\left(3+x-y\right)\)
b: \(A=x^2+6x+9-y^2\)
\(=\left(x+3\right)^2-y^2\)
\(=\left(x+3+y\right)\left(x+3-y\right)\)
a: \(A=\left(x-y\right)^2-4=\left(x-y-2\right)\left(x-y+2\right)\)
Đúng 1
Bình luận (0)
