2(x^2-xy)-3(2x^2-3xy)-2[x^2-(2x^2-xy+y^2)]求答案!

来源:学生作业学帮网 编辑:学帮网 时间:2024/04/28 17:49:25

2(x^2-xy)-3(2x^2-3xy)-2[x^2-(2x^2-xy+y^2)]求答案!

2(x^2-xy)-3(2x^2-3xy)-2[x^2-(2x^2-xy+y^2)]
=2x^2-2xy-6x^2+9xy-2x^2+4x^2-2xy+2y^2
=-2x^2+5xy+2y^2
希望对您有所帮助

2(x^2-xy)-3(2x^2-3xy)-2[x^2-(2x^2-xy+y^2)]
=2x^2-2xy-6x^2+9xy-2x^2+4x^2-2xy+2y^2
=-2x^2+5xy+2y^2

2y^2-2x^2+5xy

则x-5=0,m=0 x=5,m=0 -2ab^y-1与4ab^3的同类项则b的指数一定相同 y=3 (2x^2-3xy 6y^2)-m(3x^2-xy 9y^2) =(2×5^2-3×5×