Question 589340
Let x = dimes

Let x + 7 = quarters

We multiply the value of a dime which is 10 by x to get 10x.

We also multiply the value of a quarter which is 25 by (x + 7) to get
25(x + 7).


10x + 25(x + 7) = 315

10x + 25x + 175 = 315

35x + 175 = 315

35x = 315 - 175

35x = 140

x = 140/35

x = 4

There are 4 dimes.

The amount of quarters is 7 more than 4 or 11.

The Prove:

We know that 4 dimes = 40 cents.

We also know that 11 quarters = 2.75.

So, 2.75 + 0.40 = 3.15

Did you follow?