Question

Viết thành dạng tích: A)x^2-6x-y^2+9 B)25-4x^2-4xy-y^2

Answer 1

\(A,=\left(x^2-6x+9\right)-y^2=\left(x-3\right)^2-y^2=\left(x-y-3\right)\left(x+y-3\right)\\ B,=25-\left(4x^2+4xy+y^2\right)=25-\left(2x+y\right)^2=\left(5-2x-y\right)\left(5+2x+y\right)\)

Answer 2

A) = (x^2-6x+9)-y^2

= (x-3)^2-y^2

= (x-y-3)(x+y-3)

B) = 5^2 - (2x+y)^2

= (5-2x-y)(5+2x+y)