已知A=5a-3b,B=-6a+4b,则A-B等于 A.-a+b,B=11a+b C.11a-7b D -a-7b
问题描述:
已知A=5a-3b,B=-6a+4b,则A-B等于 A.-a+b,B=11a+b C.11a-7b D -a-7b
答
A-B
=(5a-3b)-(-6a+4b)
=5a-3b+6a-4b
=11a-7b
选C