4 x+9=13 X=4 subtract 9 from the 9 and 13 and 13-9 =4 so x=4
Answer: $25
Step-by-step explanation:
For this case we must solve the following system of equations:

To solve we follow the steps below:
We multiply the second equation by -3:

Thus, we have the equivalent system:

We add the equations:

We look for the value of the variable "y":

Thus, the solution of the system is given by:

Answer:
