rain0837
幼苗
共回答了13个问题采纳率:84.6% 举报
2x²-[-3(-1/3x²-2/3xy)-2y²]-2(x²-xy+2y²)
=2x²-[x²+2xy-2y²]-2x²+2xy-4y²
=2x²-x²-2xy+2y²-2x²+2xy-4y²
=2x²-2x²-x²-2xy+2xy+2y²-4y²
=-x²-2y²
=-1²-2*1²
=-1-2
=-3
3a²-[4ab²-5(ab²+5/3a²)-3/2ab²]-a²b
=3a²-[4ab²-5ab²-25/3a²-3/2ab²]-a²b
=3a²-[-ab²-25/3a²-3/2ab²]-a²b
=3a²+ab²+25/3a²+3/2ab²-a²b
=3a²+25/3a²+ab²+3/2ab²-a²b
=34/3a²+5/2ab²-a²
1年前
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