2x+5y=16 4x+7y=26
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y
方程2分之x+y+2分之x-y=7,4(x+y)-5(x-y)=2
解二元一次方程{5X-2y=3 X+6y=7 {5x+4y=-3 2x-3y=8 {x+Y+Z=26 x-Y=1 2x-
1 .{5X-2y=3 X+6y=7 2.{5x+4y=-3 2x-3y=8 3.{x+Y+Z=26 x-Y=1 2x-
x*x+4y*y+2x*x-4y+2=0求根号下5x*x+16y*y的值快啊
方程组 x+5y+2=06x-7y=16x=y=
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
2x+5y=16 4x+7y=26
若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*