解x-y=50,y-70=3\5(x+70)+10
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
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
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
2X(x-150)=5X(3y+50) 10%x+6%y=8.5%X800怎样解?
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy)
解二元一次方程1.x+y=3 2.x-y=-5 3.x=3y 4.4x-3y=17 5.3x+y=10 x-y=2 3x
解3元一次方程组:x+y+z=70 x/30+y/20+z/40=2/5 x/40+y/20+z/30=10/23