当a=0.8,b=0.5,9a+8b-5a-6如何简算

问题描述:

当a=0.8,b=0.5,9a+8b-5a-6如何简算

=4a+8b-6
=4*0.8+8*0.5-6
=3.2+4-6
=1.2