(x+y)=36 x-4=y+2 怎样算

x+y=36；x-（y-x）=3/4x. 怎样算 (x+y)=36 x-4=y+2 怎样算 y=6x 4：x=0.5:y y=x y=2:8 y=5x+1怎样算? 4x方y/(x-2y)(x+2y)怎么算[x方/x-2y]-4x方y/(x-2y)(x+2y)=? 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 下列等式的右边是怎样从左边得到的?2x(x-y)^7/4y(y-x)^6=x(x-y)/2y (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x-4y)(2x+y)= (2x-y)²-4(x-y)(x+2y)请告诉我过程以及怎样算的,我是这样算的：2x²+y²+(4x+4y)x+2y=2x²+y²+4x²+6xy+4xy+6y²=2x²+4x²+4x²+y²+6y²+6xy=10x²+7y²+6xy这么做我知道错了, y'=（y/x）^2+y/x+4微分方程 x*x+2x+y*y-4y+5=0 x= y= 如果|X|=4 |Y|=2 且|X+Y|=X+Y 求X+Y (x+y)^2(x-y)^2(x^4+x^2y^2+y^4)=? {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11