(87.1*40+42X)/(40+42)=85
5x÷8-3x=40 7x-8=42+3x 9x+7-3x=9x-3
X减40%X等于42 怎解?
x+{40-[42-(18-x)]}怎么算
解方程21%=42 45%x-20%x=200 x-40%=360 5分之x+x=360
56-x =x- (40-x)
X/(x-30)=(x+40)/X解方程,
(X+X*20%)-[(1200-X)-(1200-X)*20%]=40%
X+X*20%-(1200-X)-(1200-X)*20%=40%
解方程((13x-x^2)/(x+1))(x+(13-x)/(x+1))=42
x/2+x/6+x/12+x/20+x/30+x/42=1
(13x-x^2)/(x+1)[x+(13-x)/(x+1)]=42
解一元一次方程 x/2+x/6+x/12+x/20+x/30+x/42=6