方程组 x+y=18 { (x+0.12x)+(y+0.1y)=20
解方程组(三分之x+y)+y=6,3(x+y)-y=24
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
解方程组x+y=15 (x+15%x+y+10%y)=17
10/x+y+3/x-y=-5 15/x+y-2/x-y=-1(用换元法解此方程组)
方程组x-y=500① x+15%-(y-10%y)=950②
解方程组:x-y=20 (x+10)÷(y-10)=5
已知方程组2x-y=10,x+2y=11,求(2x-y)³-(2x-y)²(x-3y)的值
解方程组1/(x-y)-1/(x+y)=3/20,2/(x+y)+3/(x-y)=19/20
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
解方程组x+y+√(x+y)=20;x²+y²=136
已知方程组4x+2y=1,20x+8y,求x,y
1.方程组x+y+2=18