Solve the equation. show all work

18^ (r-10) = 93

Recall the logarithm rules:

a^y = x is the same as log_a x = y

In this case,

a = 18

y = r - 10

x = 93

So,

18^ (r-10) = 93

is the same as

log_18 93 = r - 10

Solve for r to get:

10 + log_18 93 = r