『4x+9y=97 5x+5y=65』『0.2x+0.3y=4.6 0.7x-0.5y=0.6』

『4x+9y=97 5x+5y=65』『0.2x+0.3y=4.6 0.7x-0.5y=0.6』 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 5x-4y(y-x)=? 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 x+y／y=5／4,则x／y=---------------- 已知：4x = 5y,求(x+y) ：y （5x+3y)(3y-5x)-(4x-y)(4y+x)= x*x+2x+y*y-4y+5=0 x= y= 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 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 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 (x-y)/4+(x+y)/5=1/4 (x+y)/9-(x-y)/3=//2(x-y)/4+(x+y)/5=1/4(x+y)/9-(x-y)/3=//2 y=|-x.x+4x+5| 5X+16X= Y+9Y= X+7X-4X= 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?