推导公式:(x+y)(x2-xy+y2)=x3+y3.
推导公式:(x+y)(x2-xy+y2)=x3+y3.
已知x3+y3=(x+y)(x2-xy+y2)称为立方和公式,x3-y3=(x-y)(x2+xy+y2)称为立方差公式,
已知:x+y=1,xy=-3,求下列各式的值:(1)x2+y2; (2)x3+y3; (3)x5y+xy5.
已知x3+y3-z3=96,xyz=4,x2+y2+z2-xy+xz+yz=12,则x+y-z=( )
若x+y=10,x3+y3=100,则x2+y2=______.
解方程组:y2=x3-3x2+2x;x2=y3-3y2+2y
已知A(X1,Y2)B(X2,Y2)C(X3,Y3)在y=2^x 上 X1+2X2+3X3=1 则Y1+Y2^2+Y3^
已知x+y+z=1,x2+y2+z2=2,x3+y3+z3=3,求xy(x+y)+yz(y+z)+zx(z+x)的值
不等式选讲设x,y,z为正数,证明:2(x3+y3+z3)≥x2(y+z)+y2(x+z)+z2(x+y).
(x1+x2+X3+x4)/(y1+y2+y3+y4)用什么公式和x1/y1,x2/y2,x3/y3,x4/y4
已知x+y+z=2,x2+y2+z2=12则x3+y3+z3=
x+y=10,x3+y3=100,则x2+y2=?