If a=4b^2 and b=-1/2e^2, what is the value of a to the nearest tenth?

To answer, it is assumed that e here is the Euler number which is equal to 2.718. Substitute this value to the e of the second equation to get the value of b.
                                 b = 0.5(2.718^2)  = 3.6945
Then, we substitute this value to the first equation to get the value of a.
                                        a = 4(3.6945^2) = 54.498
Thus, the answer is approximately equal to 54.5. 

Ci think but i'm not entirely sure so..