Question 569367
How do you solve for x in the equation 
7.2^x-4=8.21?
7.2^x=8.21+4=12.21
take log of both sides
xlog7.2=log12.21
x=log12.21/log7.2
using calculator
x≈1.2676
..
Check:
7.2^1.2676-4≈8.21