We are looking for the solution to the equation ex=8, which means the x-value for which the graph of ex has an y-value equal to 8. Thus, we can find by drawing a straight line for y=8 and see where it intersects the graph. Then we read the x-value.
We see that the x-value lies between 2 and 2.25, which, rounded to the nearest integer, equals 2. The solution to the equation is then x≈2.
Let's rewrite e as e1, which means that x=1 in the function y=ex and obtain the value of e. You then read the graph's y-value when the x-value equals 1.
From the graph you see that the y-value lies approximately at 2.7 for x=1, which gives that e≈2.7.