Quandaries
and Queries 

Name: Keisha Secondary I need to solve this problem by using the substitution method. I also have the following
question as well: Thanks in advance Keisha 

Hi Keisha, The substitution method means that you start with one of the equations, use it to solve for one of the variables in terms of the other, substitute into the other equation and then solve this equation. So let's try it with your first problem. Select one of the equations and use it to solve for one of the variables in terms of the other:
Substitute into the other equation
Solve this equation
You are almost done. You know y = 2 and you need to find x. Use the second equation you started with.
For the second problem I would think in terms of cents rather than dollars.
Let the number of dimes be d and the number of quarters be q. There are 25 coins in all so
Each dime is worth 10 cents so the value of the dimes is 10d cents. Each quarter is worth 25 cents so the value of the dimes in 25q cents.Hence
Now use the substitution method to find q. Penny 

