If you're using log:
Swap both sides: 1100 · 1.7^n = 7000
Divide both sides by 1100: 1.7^n = 70/11
Concert decimal to a fraction: (17/10)^n = 70/10
Take the log of both sides. (Put 17/10 into the subscript of log like the picture shows)
The answer is the decimal.
