- 4a²-b²=32,2a-b=4,则3a-b的值是..

问题描述:

- 4a²-b²=32,2a-b=4,则3a-b的值是..

4a(2)-b(2)=32
(2a+b)(2a-b)=32
将2a-b=4
则,2a+b = 8
则 a= 3,b=2
则,3a -b = 7