Question

if Log10^a=4 what is a

Answer 1

recall that log and ^ are inverse operations:

10^(log x) = x
log(10^x) = x

so, now you can do

10^(log_10(a)) = 10^4
a = 10^4

Answer 2

Log10^a = 4.
10^a = 4,
a = 4.