X*1+1.5X *Y = 180 180 / X -(1+Y) = 40/60 这个方程怎么解

[3x^2-(x+y)(y-x)][2(-x-y)(y-x)+2x^2+3y^2],其中x=-2分之1,y=1.5 x>=1,x-y y=x-1(x 求导 y=[x/(1+x)]^x 18x/34y=9/1 x/y=?/? 1.5（x+y）+3（x-y）=27（x+y）-3（x-y）=-62.x-y/7 - x+y/10 =1/22(x-y)-5(x+y)=3所谓细节决定成败, y'-(1/x)y=xe^-x 2x-1-3(y-2)=x 2(x-1)-y=4y-18, 2x-1-3(y-2)=x 2(x-1)-y=4y-18, X+y+z=26,x-y=1,2x-y+z=18 z=0.015x*x+y*x*0.05+(1-x-y)*2.5*(x+y) x>0.35.xy>0.70x+y 已知|3x+y-0.5|+(x+2y+1.5)^2=0,求代数式（x-y)(x-2y)-3x(1/3x-y)+(2x+y)(2x-y) 快. 3x-y+x=3 4【X-y-1】=3【1-y】-1 5x-4y+4x=3 2x+y-3x=11 【 x除以2 】-【y 除以3】 =2 2x+7y-3x=19 x+y+x=12 3x+2y-x=18 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 x.y都是自然数,且x(x-u)-y(y-x)+12,求x.y得值快1且x(x-y)-y(y-x)=12 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 y'/y=1/x y(x+y)+(x-y)²-（x+y）（x-y）,其中x=-1/3,y=3