(5a²-3b²)-3(a²-b²)-(-b²),其中a=3,b=-2化简

问题描述:

(5a²-3b²)-3(a²-b²)-(-b²),其中a=3,b=-2化简

=2a²-3a²-3b²+b²
=-2b²-a²

(5a²-3b²)-3(a²-b²)-(-b²)=5a²-3b²-3a²+3b²+b²=(5a²-3a²)+(3b²-3b²+b²)=2a²+b²=2x(3)²+(-2)²=18+4=22