18+x+(x+2.5)+15.5=y解方程

18+x+(x+2.5)+15.5=y解方程 解方程组；1.x+y+z=26,x-y=1,2x-y+z=18 2.5x+y+z=1,2x-y+2z=1,x+5y-z=4. x+2.5-y=7-y 求未知数X y+x+13.2=18+y 求未知数X 解方程 x(x+y+z)=6 y(x+y+z)=12 z(x+y+z)=18 解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18 解方程组24/(x+y) +24/(x-y) = 7/3 ,8/(x+y) +18/(x-y) = 4/3 解方程组：2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66 解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66 如何解x+y＞11,10x+y-18=10y+10x 如何解x+y>11,10x+y-18=10y+x z=0.015x*x+y*x*0.05+(1-x-y)*2.5*(x+y) x>0.35.xy>0.70x+y 根据x=3y填表 x=3 x=?x=18 x=?x=90 x=?x=?y=?y=2 y=?y=4 y=?y=12 y=2.5不对！是x=3 y=？x=？y=2 x=18 y=4，x=？y=4，x=90 y=？x=？y= 12，x=？y=2. x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 解方程:x/v-x/(y+8)=27/60,x/(y-4)-x/y=18/60 解方程组 1.3(x+y)-4(x-y)=4,x+y/2 + x-y/6 =1 2.5x+4y+z=0,3x+y-4z=11,x+y+z=-2 化简 x / y(x+y) - y / x(x+y) = y=x(x