Use photo math it works well
Answer:

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:

This should be the correct answer. I recommend Desmos.
G(x)= -9(0)-15
G(x)= -15
The answer is -15