Can you do Test 6 section 4 number 37? I always miss this kind of question!

The best way to be sure you’re not missing the mark on a question like this is to *actually list the years* rather than just trying to capture everything in an equation. So say he starts with *x* dollars on January 1, 2001. You know his money doubles each year, so you can write the following.

January 1, 2001: *x*

January 1, 2002: 2*x*

January 1, 2003: 2(2*x*) = 4*x
*January 1, 2004: 2(4

*x*) = 8

*x*

January 1, 2005: 2(8

*x*) = 16

*x*

Of course, you know from the question that on January 1, 2005, Jeremy really had $480 in his account. Easy enough to solve from there:

16*x* = 480

*x* = 30

The unnecessarily complicated way to do this question is with an exponent formula. You know his money doubles every year for 4 years, so you can write:

Of course, that just simplifies to the same equation we just solved: 16*x* = 480.