x 45 44 43 42 41 40 y=50 60 70 80 90 100

x 45 44 43 42 41 40 y=50 60 70 80 90 100 X=20时y=66 X=30时y=50X=40时y=40x=50时y=33x=60时y=28x=70时y=25x=80时 80y+100y=x+60(y+10)+100(y+10) 这个方程怎么解? X除以40+Y除以100=1且X小于15,Y小于70,求X和Y x+y=40 z+x=50 z+y=60 问 x.y.z是多少? 将下列数据拟合成方程x=20,30,40,50,60,70,80,90,100,110,120y=0,0,43,143, x+80%y=42 y-x=12 用二元一次方程解出来,20+60x+80y=70,20+80x+90y=80 x+y=450;40%x+30=60%y 解方程.100/(X+Y)+64/(X-Y)=9;80/(X+Y)+80/(X-Y)=9 Y-X=45 (80%Y-X)×8=(Y-35-X)×12 70（Y+60）=X 100(Y-30)=X 怎么解