已知32m=5,3n=10,求9m-n和92m-n.

问题描述:

已知32m=5,3n=10,求9m-n和92m-n

解;32m=9m=5,3n=[(3n2] 

1
2
=(9 
1
2
n=100
9m-n=9m÷9n=5÷
10
=
10
5

92m-n=92m÷9n=25÷100=
1
4