x/5-y/2=2 2x+3y=4 怎么算

二元一次方程(x+y)/2+(x-y)/3=6,4(x+y)-5(x-y)=2怎么算 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 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 4x方y/(x-2y)(x+2y)怎么算[x方/x-2y]-4x方y/(x-2y)(x+2y)=? 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 x^2-4xy+3y^2=（x-3y)(x-y)x^2-4xy+3y^2 怎么分解成（x-3y)(x-y) 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y怎么解 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 3X=5Y （X+Y)*3X=(2Y+X)*4+2*2 {2X=5(X+Y)3X-10(X+Y)=2怎么解? 3x*5y+2x*6y=2.7*(3x+2x)怎么解 2x=y 3y=x怎么解 x-3y=2 y=x 怎么写