1.6x=5y300+4x+100=4y2.4(x+y)=805(x-y)=803.y-x=45(85%y-x)8=(y-35-x)x24.0.7(1+40%)x+0.9(1+40%)y=399(1+40%)x+((1+40%)y=4905.x+y/2=502/3x+y=506.x+y=3002.89%乘3x+2.7%乘3y(1-20%)=32338.2-30000

1.6x=5y300+4x+100=4y2.4(x+y)=805(x-y)=803.y-x=45(85%y-x)8=(y-35-x)x24.0.7(1+40%)x+0.9(1+40%)y=399(1+40%)x+((1+40%)y=4905.x+y/2=502/3x+y=506.x+y=3002.89%乘3x+2.7%乘3y(1-20%)=32338.2-30000 y=|-x.x+4x+5| 5x-4y(y-x)=? x-y+5x-4x= ?x-y+5x-4x= ? （5x+3y)(3y-5x)-(4x-y)(4y+x)= x*x+2x+y*y-4y+5=0 x= y= 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? x+y／y=5／4,则x／y=---------------- 已知：4x = 5y,求(x+y) ：y 1:4(x-100)+3y=5 2:6(x-y)-2(x+y )=14 x-100=-y 3(x-y)+(x+y)=5 先无视上面的1.4(x-100)+3y=5x-100=-y2.6(x-y)-2(x+y )=143(x-y)+(x+y)=5 x+x+x+y=60 .x-y=4 化简求值：2(x+y)(x-2y)-2x(x+y),其中x、y满足x^2+y^2-2x+4y=-5 5X+16X= Y+9Y= X+7X-4X=