7y(x-3y)的平方-2(3y-x)的立方-搜答案-智慧作业帮

4x^2-3y^2=73x^2+2y^2=19相加7x^2-y^2=26所以14x^2-2y^2=2(7x^2-y^2)=2*26=52

(x+y)的平方-2x-2y-3=(x+y)的平方-2(x+y)-3=(x+y-3)(x+y+1)

2(y-x)²-7(x-y)+6(x-y)-3(y-x)²=-(y-x)²-(x-y)=-(x-y)²-(x-y)=-(x-y)[(x-y)+1]=(y-x)(

4/x-15x²y再问：朋友，发一下过程再答：3x²y-(-3x)²×(2y)+x³y²/(x²x²y²/4)=3x&#

（x+y）(x+2y)=x²+xy+2xy+2y²=x²+3xy+2y²

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

原式=9x⁴/16y²*2y/3x+x²/2y²*x/2y²=3x³/8y+x³/4y⁴=(3x³y

3a(x-y)-2(y-x)^2=3a(x-y)-2(x-y)^2=(x-y)[3a-2(x-y)]=(x-y)(3a-2x+2y)

3(x-y)²*(y-x)²*2(x-y)=6(x-y)^(2+2+1)=6(x-y)^5再问：需要再详细一点的过程再答：3(x-y)²*(y-x)²*2(x-

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

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

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

x(x-y)²-(y-x)³=x(x-y)²+(x-y)³=(x-y)²[x+(x-y)]=(x-y)²(2x-y)

原式=X²-9Y²-(X²-2XY-4Y²)-(4X²-4XY+Y²)=X²-9Y²-X²+2XY+4Y&su

先由两已知方程解得x=27/8,y=9/8,然后接下来的自己算啦...两方程的话,先将第二个两边都乘三,再于第一个相减得出y,再将y带进方程得x

1.(2x-3y)^2-(y+3x)(3x-y)=4x^2-12xy+9y^2-(3x+y)(3x-y)=4x^2-12xy+9y^2-9x^2+y^2=10y^2-5x^2-12xy2.[(x-y)

-2(x-y)^2-3(x-y)+5(y-x)^2+4(y-x)=-(x-y)(2x-2y+3)+(y-x)(5y-5x+4)=(y-x)(2x-2y+3)+(y-x)(5y-5x+4)=(y-x)(

(x+2)^2-(y-3)^2=(x+y)*(x-y)x^2+4x+4-y^2+6y-9=x^2-y^24x+6y-5=0即为所求的方程

X=3+Y,将其带入X+Y=7也就是3+Y+Y=7,Y=5带入X-Y=3也就是X-5=3,X=8所以X的平方+Y的平方=X乘以X+Y乘以Y=8乘以8+5乘以5=64+25=89x的平方+y的平方=89

(3x-y)的平方-(2x+y)的平方-5(x-y)=(3x-y+2x+y)(3x-y-2x-y)-5(x-y)=5x(x-2y)-5(x-y)=5x^2-10xy-5x+5y