鑻2+xy=2,y虏+xy=3锛屽垯x虏+2xy+y虏=
(-3x^y+2xy)-( )=4x^+xy
已知x-y=4xy,则2x+3xy-2yx-2xy-y
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少?
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
已知xy^2=-2 求-xy(x^2y^5-xy^3-y)
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
X²+2xy+y²/xy乘x²-2xy+y²/xy+y²=
(x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2
(x+2y-3xy)-(-2x-y+xy),其中x+y=,xy=-,求值.
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)