(3x-2y+1)(3y+2y-1)怎么算

(x-2y)^m+1/(x-2y)^m-3/(2y-x)^3怎么算 (x+y)(x-y)+3y^2怎么做? (2x^3y^3-2x^3y+1/8^4+y)/(-1/2x^3y)怎么算! x-y=2y 0.2x+3y=1 这个二元一次方程怎么解? x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 二元一次方程 ：2(x+y)-(x-y)=3 (x+y)-2(x-y)=1 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 变量x,y满足约束条件,x+y>=3,x-y>=-1,2x-y (Y-X)^3*(X-Y)^m+(X-Y) ^m+1*(Y-X)^2 (x-y)^2+(x+y)(x-y) 其中 X =3 Y=-1 y^3+(x+2)e^y=1 y''(-2) y-1/2-y+1/3≥y怎么做 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x)