4x-3y=14 5x+y=27
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
解方程组 {3(x+y)-4(x-y)=11 {2(x-y)+5(x+y)=27全过程、快
解方程组 {3(x+y)-4(x-y)=11 {2(x-y)+5(x+y)=27
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
x+2y=-5&2x-5y=-1.3x=5y&2x-3y=-1 .2x+4y=11&3y-2y=3 .2x+3y=14&
{3x-2y=3,2x+2y=17 {4x-2y=14,5x+y=7 {x+3y=6,2x-3y=3 {2x+3y=11