Question

2的m次方=5的n次方=10求m+n

Answer 1

因为2^m = 5^n = 10

所以 m = log(2 10) n = log(5 10) (log(2 10)表示2为底10的对数,log(5 10)表示5为底10的对数）

因此 m + n = log (2 10) + log(5 10) = 1/lg2 + 1/lg5＝1/(lg2*lg5)