用加减消元法求23x+17y=63,17x+23y=57,求xy=?
用加减消元法求23x+17y=63,17x+23y=57,求xy=?
已知X+Y=17,XY=42,求X^2y+xy^2的值
用加减消元解方程 2x+3y=12 3x+4y=17
4(x+2)=1-5y 3(y+2)=3-2x和x+y=420 30%x+40%y=160x80% 两个 求xy用加减消
已知x,y均为实数,且满足XY+x+y=17,xy²+x²y=66,求x²+y²
已知x,y均为实数,且满足xy+x+y=17,x^2y+xy^2=66,求x^2+y^2的值.
已知x、y均为实数,且满足xy+x+y=17,x^2y+y^2x=66,求x^4+x^3y+x^2*y^2+y^3x+y
x^2+xy+x=36,y^2+xy+y=20,求x+y.
如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值.
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
xy=2010,x+y=2009,求x,y
已知x+y=17,xy=60 求x^2+y^2 及(x+y)^2