Can someone give me a hand?

First, add 84 to both sides, to isolate the exponential function.

Then, take the logarithm of both sides:

(2x+3)*log 5 = log 84

Solving for 2x+3, we get log 84 - log 5, and so

2x = -3 + log 84 - log 5.  Dividing both sides by -3, we obtain the final

      -3 + log 84 - log 5

x =

                    2

You could make a frequency chart or draw a graph.