5X+3=11Y 2X+16=10Y
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
{2x+y+Z=10 {2x+4y+3z=9 {2x+2y+2=16{3x+2y+5z=11 {x+y+2z=8{5x+
解方程组 10(x-y)=3(x+y)+15 6(x+y)=4(2x-y)+16
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
已知x,y满足约束条件{2x+5y>=10,2x-3y>=-6,2x+y
{ x-y/7-x+y/10=1/2 {2(x-y)+5(x+y)=3
10/x+y+3/x-y=-5 15/x+y-2/x-y=-1(用换元法解此方程组)