The value of the underlined digit depends on the place the number that is underlined is. For the first digit, it would be ones. The second digit is 10s. The third is 100s and the fourth is thousands and the fifth is ten thousands and the 6 is hundred thousands, and the seventh is million, and so on.
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.
You can find a common denominator using the two denominators multiples.
The answer is Y equals -7+5x