Can someone me with this math question pls?

If it doubles each year, it means that the next year the number will be 2 times its size.

So if in 2005, the number of users is 2 million, then in 2006 the number of users will be 2 times the number in 2005.

Knowing this, we then know that the year 2004 will be half the users of 2005. Then the year 2003 will be half the users of 2004 and so forth.

So you solve for each year as such:

2005: 2

2006: 2 x 2 = 4
2007: 4 x 2 = 8
2008: 8 x 2 = 16
2009: 16 x 2 = 32

2004: 2 / 2 = 1
2003: 1 / 2 = 0.5
2002: 0.5 / 2 = 0.25
2001: 0.25 / 2 = 0.125

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )