5y-3=2y+4-6y y=?

问题描述:

5y-3=2y+4-6y y=?

=x^2-5xy+6y^2-(9x^2-12xy+4y^2) =<4x^2-(5y-3)^2> = -8x=(2x)^2-(5y-3)^2 =4x^4-25y^2+30y-9 2 (x-2y)(x-3y)-(