去括号并化简1.4xy²-3x²y-{3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)]}2.(3a³-2a²+5a+7)+(-2a²-½a+3)-(-4a³+½a²+6a-5)

去括号并化简1.4xy²-3x²y-{3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)]}2.(3a³-2a²+5a+7)+(-2a²-½a+3)-(-4a³+½a²+6a-5)
去括号并化简
1.4xy²-3x²y-{3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)]}
2.(3a³-2a²+5a+7)+(-2a²-½a+3)-(-4a³+½a²+6a-5)

去括号并化简1.4xy²-3x²y-{3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)]}2.(3a³-2a²+5a+7)+(-2a²-½a+3)-(-4a³+½a²+6a-5)
4xy²-3x²y-{3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)]}
解:原式= 4xy²-3x²y-{3x²y+xy²-2xy²+4x²y-x²y+2xy²}
=4xy²-3x²y-3x²y-xy²+2xy²-4x²y+x²y-2xy²
=3xy²-9x²y