已知x-y不等于0,x^2-x=7,y^2-y=7,求x^3+y^3+x^2y+xy^2的值

来源：学生作业帮助网编辑：六六作业网时间：2024/11/15 19:30:51

已知x-y不等于0,x^2-x=7,y^2-y=7,求x^3+y^3+x^2y+xy^2的值已知x-y不等于0,x^2-x=7,y^2-y=7,求x^3+y^3+x^2y+xy^2的值已知x-y不等于

已知x-y不等于0,x^2-x=7,y^2-y=7,求x^3+y^3+x^2y+xy^2的值
已知x-y不等于0,x^2-x=7,y^2-y=7,求x^3+y^3+x^2y+xy^2的值

已知x-y不等于0,x^2-x=7,y^2-y=7,求x^3+y^3+x^2y+xy^2的值
已知x-y≠0,x²-x=7,y²-y=7,求x³+y³+x²y+xy²的值.
经观察可知,x、y相当于是方程t²-t=7的两个不等实根,方程整理为：
t²-t-7=0
由韦达定理,得：
x+y=1
xy=-7
所以：
x³+y³+x²y+xy²
=(x³+y³)+(x²y+xy²)
=(x+y)(x²+y²-xy)+xy(x+y)
=(x+y)(x²+y²)
=x²+y²
=(x+y)²-2xy
=1-2*(-7)
=1+14
=15

已知x-y/x=x/x-2y（y不等于0）,求x：y的值已知x-y/x=x/x-2y(y不等于0),求x：y的值已知x-y不等于0,x^2-x=7,y^2-y=7,求x^3+y^3+x^2y+xy^2的值已知X-Y不等于0,X^2-X=7,Y^2-Y=7,求X^3+Y^3+X^2Y+XY^2的值已知x^2+xy-2y^2=0 (x不等于0,y不等于0）,求x/y-y/x-(x^2+y^2)/xy的值已知x*x-2xy-3y*y=0且x不等于0 y不等于0,那么5x-4y/5x+4y= 已知z不等于0,x、y、z满足4x-7y-5x=0,2x-y-z=0.求x：y 已知x平方+2xy-8y平方=0(y不等于0),求x-y/x+y的值已知x平方+2xy-8y平方=0(y不等于0),求x-y/x+y的值已知x+y-7z=0 x-2y+5z=0(xyz不等于0）,求x+2y-z/y-2x+12z 已知xyz不等于0,且x+2y-z=0,7x-y-z=0,求x+y+z/2x-y-z的值. 已知x=3y,z=7x（x不等于0）,求代数式2x+3y-z分之x+y+z的值已知2x^2+5xy-7y^2=0,且y不等于0 求x/y的值已知5x-4y=0且xy不等于0,求x^2+y^2/x^2-y^2-x+y/x-y的值已知x^2-6y^2=-xy,x>0,y>0且x不等于y.则（x+3y）/（x-y）的值为_____? 已知x平方+xy-2y的平方=0,x,y不等于0,求x/y-y/x-x的平方+y的平方/xy 已知(4x-3y)(4x-3y)=(3x-2y)(3x-2y),并且xy不等于0,求x除以的y值已知x,y互为相反数,且xy不等于0,则3x+y分之7x+3y=?