分解因式3(x y)的平方-27-搜答案-搜搜考试网

3x²+5xy-2y²+x+9y-4用待定系数法做因为3x²+5xy-2y²=(3x-y)(x+2y)所以设3x²+5xy-2y²+x+9y

（x-y）（x-y-2）-3

答：-x³y+2x²y-xy=-xy(x²-2x+1)=-xy(x-1)²

3x(x^2-2)y^2+6xy^2+9x^2y^2再问：O(∩_∩)O谢谢再答：原式=3x^3-6x^2y+3xy^2提取公因式，得3x(x^2-2xy+y^2)由完全平方公式，得3x(x-y)^2

原式=-y(4x²-4xy+y²)=-y(2x-y)²

3x³-6x²y+3xy²=3x(x²-2xy+y²)=3x(x-y)²

求根法：x^2+xy-2y^2+2x+7y-3=x^2+x(y+2)-2y^2+7y-3,△（x)=(y+2)^2-4(-2y^2+7y-3)=9y^2-24y+16=(3y-4)^2,x1=[-(y

7x²+3Y+XY+21X=7x²+21X+（3Y+XY）=7x（x+3）+Y（3+X）=（x+3）（7x+Y）

1x²+2xy-3y²=x²+2xy+y²-4y²=（x+y）²-(2y)²=(x+y+2y)(x+y-2y)=(x+3y)(x-

3x立方+12xy平方=3x(x²+4y²)

=7x²-4x²+4xy-y²=7x²-(2x-y)²=(√7x+2x-y)(√7x-2x+y)本题答案不唯一的

x^3z-4x^2yz+4xy^2z=xz(x^2-4xy+4y^2)=xz(x-2y)^2(x+2)(x+3)+3x+1=x^2+3x+2x+6+3x+1=x^2+8x+7=(x+1)(x+7)x^

第一题：可把x看作未知数,y当做一个已经知道的数字,可化为x^2+(3y+4)x+(2y^2+5y+3)可用十字相乘,得12y+3(要得到3y+4,可将2y^2+5y+3分解为（2y+3）（y+1））

3x²+5xy-2y²+x+9y-4=3x²+(5y+1)x-(2y²-9y+4)=3x²+(5y+1)x-(y-4)(2y-1)=(3x-y+4)(

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

原式=(x+y)(x+2y)+2(x+2y)=(x+2y)(x+y+2)希望我的回答能帮助到您,

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

4x³-xy²=x(4x²-y²)=x[(2x)²-y²]=x(2x+y)(2x-y)

2x^2+3xy-2y^2-x+8y-6=(x+2y)(2x-y)-x+8y-6=(x+2y-2)(2x-y+3)

-3x的平方+6xy-3y的平方=-3(x²-2xy+y²)=-3(x-y)²请点击下面的【选为满意回答】按钮,