若x-y=5,xy=6 则x²y-xy²=—————,2x²+2y²______

若x-y=5,xy=6 则x²y-xy²=—————,2x²+2y²______ 化简（X²+2XY+Y²）（X²—XY+Y²）² (x+y)(x²-xy+y²）—xy（x+y）因式分解 若x+y=10 xy=-1 则x²+y²=(x+y)²-2xy= X²+2xy+y²/xy乘x²-2xy+y²/xy+y²= 已知实数x,y满足5x²+2y²+1=6xy+4x-2y,则x²-xy+2000y (-x²+2xy-y的平方)-2(xy—3x²)+3(2y的平方-xy) 计算. A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y,若x= 设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若x 若x-y=1,xy=5,则x²y-xy²=? 先化简,再求值：3x²—[2x²y—（xy—x²）]+4x²y,其中x=—1,y 若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy(