已知A=7ab-3a²b²+7+8ab²,B=3a²b²-3-7ab,则A-b=( )
问题描述:
已知A=7ab-3a²b²+7+8ab²,B=3a²b²-3-7ab,则A-b=( )
答
A=7ab-3a²b²+7+8ab²,
B=3a²b²-3-7ab
A-B=7ab-3a²b²+7+8ab²-(3a²b²-3-7ab)
=7ab-3a²b²+7+8ab²-3a²b²+3+7ab
=-6a²b²+8ab²+14ab+10