- 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..
答
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