If I invest $10 for example, and I make 1% extra per day, what would the equation be?

1 Answer
Jun 5, 2016

#y = 0.01x + 10#


Let's start out by creating a logical expression.

You start out with $10. You also know that you make 1% every day.
Lets write this out in the most reasonable way.

#1% = 0.01#

So, we can establish #0.01x# to represent the 1% you get daily, #x# being the amount of days. To say this expression in words, it would sound like: "I make 1% every day".

Now we need to account for the $10. Well we know that it is the money you start out with, and the 1% is based off of that. So, we can keep it simple and write: #0.01x + 10#.

It does seem to make more sense to put the 10 before the 0.01, but mathematically, this is the more traditional way of writing these kinds of functions. This new expression can be read as: "I make 1% of 10 dollars every day".

We have a beautiful expression now! We just need to set it as an equation , because it does not have an equal sign just yet.

#0.01x + 10 = y#
or #y = 0.01x +10#

And there's your equation!