# John has four more nickels than dimes in his pocket for a total of $1.25. How do you write an equation one could use to determine the number of dimes, #d#, in his pocket.?

##### 1 Answer

#### Explanation:

In this case, you would not write *an* equation, you would write *two* equations. This will give you a system with two equations and two unknowns. The equations will be linearly independent, meaning you'll be able to use them to solve for

First, we know that John has four more nickels than dimes. Let

Additionally, we know that our change totals

We then have the two equations:

We will substitute the first into the second, giving

This gives us our answer; we have