Question

Jillian has $50 that she plans on investing in an account that will double her money every week. This can be represented by the equation M = 50(2)x where M represents the amount of money she has and x represents the number of weeks that have passed. If she invested it in an account that tripled her money every week, what should be changed in the equation M = 50(2)x to represent the new situation?

Answer 1

The part that would change would be the number 2.  It would become a 3 instead of the 2.  Tripling something means to have 3 groups of it.

The reason is that the $50 is not changing, nor would the number of weeks, x be changing.

Answer 2

Answer: c  Replace the 50 with a 450.

In M = 50(2)x the 50 represents the amount of money she started with and the 2 represents that it is doubling every week. So to write an equation where she started with $450 she would need to Replace the 50 with a 450.