What you wanna do here is use a calculator, as "e" in mathematics refers to the "e" on a calculator. The tricky part about this question is that the answer for the equation is the given percentage, NOT the value for "x". From there, plug in the multiple choice answers for "x" and see which one works!
In this case, A is the correct answer. B is absurdly large, so I omitted it immediately in the attached picture.
4.
4^3 = 64
64X64 = 4096
4^6 = 4096
Let x be the certain number and that six time this number may be expressed as 6x. Based on the conditions presented above, the sum of 6x and 8 should be equal to 32. This may be mathematically expressed as,
6x + 8 = 32
Therefore, the answer is fourth choice.
40s+2bs+200=number of books needed
if we want 12 books and 8 stalls
b=12
s=8
solve
40(8)+2(12)(8)+200=
320+192+200=
712
needs 712 books