x+2y=140 4x+3y=360 3Q!
已知全集为R,集合P={y|y=x的二次方+4x+1,x∈R},Q={y|y=-x的二次方+2x+3,x∈R}求P∩Q和
数学题已知p=x^/x-y-y^/x-y,q=(x+y)^-2Y(X+Y),
x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20
{(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
(x+y)(x+2y)(x+3y)(x+4y)=-40
已知集合p={y|y=-x2+2x+5,x属于R},Q={y|y=3x-4,x属于R},求P交Q,p并Q.
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
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