a²+ab-2b²/a²-b²=( )/a+b ,x-y/2a=(y-x)
x²(x+y)(y-x)-xy(x+y)(x-y) 已知a+b=4,ab=-2,求多项式3a²b+3
已知A=2x+y,B=2x-y,计算A²-B².
已知A=2x+y,B=2x-y计算A²-B²
已知集合A={(x,y)|(y-2)/(x-1)=a+2,x,y∈R},B={(x,y)|(a²-4)x+(a
因式分解(a-b)²(x-y)-(b-a)(y-x)²=(a-b)(x-y)×( )
若集合A={(x,y)/x²+y²=1},B={(x,y)/y²=2(x+)},则A∩B=
集合A={y|y=x²-1,x∈R},B={y|y=-2x²+2,x∈R},求A∩B
集合A{y|y=x²-1,x∈R},B{y|y=-2x²+2,x∈R}求A∩B
已知:6x²-7xy-3y²+14x+y+a=(2x-3y+b)(3x+y+1)求a,b的值
已知A=x²-2xy+y,B=x²+2xy+y²-3,求2A-[B-(B-A)+2A+B]
已知实数a、b、c、d满足a+b=x+y=2,ax+by=5.求(a²+b²)xy+ab(x
已知|x-y-3|+(a+b+4)²=0,求2a+2b-(a+b)分之(x-y)²-3(y-x)的值