9-3x=5y+5?

4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 （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 5x=3y,(2x+y)的平方=5x(x+y)+9 3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) Y=x+3 7x+5y=9 y-x=3 7x+5y=-9 y=x+3 7x+5y=9 {y=x+3,7x+5y+9; (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 解方程组 3(x+y)-2(x-y)=9,5(x+y)+2(x-y)=-1 解方程组:{3(x+y)-2(x-y)=9,5(x+y)+2(x-y)=-1} 接二元一次4(x+y)-3(x-y)=9;5(x-y)+2(x+y)=11 x+y=5 2x+3y-z=9 x-y+z=4 （5x+3y)(3y-5x)-(4x-y)(4y+x)= (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27