(-3xy)(2x²-5xy-4y²)计算
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
计算:(xy-x²)×x-y/xy
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
计算:x²+2xy+y²/xy-y².x²-2xy+y²/xy+y
计算:x²y-(2xy²-5x²y)+3xy²-y³
计算:(-7x²y)(2x²y-3xy³+xy)
2x²y+{2xy-[x²y-2(﹣3x²y+xy)]﹣4xy²} 计算
计算:2x+2y分之3y + x²+xy分之2xy
(-x²+2xy-y的平方)-2(xy—3x²)+3(2y的平方-xy) 计算.
计算x²y³-2x(4xy³)
计算[5xy²(x²-3xy)-(-3x²y²)³]÷(-5xy)
计算:-2x²y(-2xy²)²+(2xy)³·(xy²)