如是我云
春芽
共回答了19个问题采纳率:94.7% 举报
解(1):原式=4a×(-2b)-b²×(-2b)
=4×(-2)×a×b-1×(-2)×b²×b
=-8ab+2b³
(2):原式=2x²×x-2x²×1/2
=2×x²×x-2×(1/2)×x²
=2x³-x²
(3):原式=5ab×2a-5ab×b+5ab×0.2
=5×2×a×a×b-5×a×b×b+5×0.2×ab
=10a²b-5ab²+ab
(4):原式=2a²×(-9a)-2/3a×(-9a)-4/9×(-9a)
=2×(-9)×a²×a-2/3×(-9)×a×a-4/9×(-9)×a
=-18a³+6a²+4a
1年前
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