Answer:
![\displaystyle [-2, 7]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5B-2%2C%207%5D)
Step-by-step explanation:
You want to eradicate one pair of variables so they are set to zero. It does not matter which pair is selected:

{½[4x + 2y = 6]
{−2x + 2y = 18
>> 
Plug this back into the system to get the x-value of 
I am joyous to assist you at any time.
Y=2/3x+2/3
I hope this helps!
Simple....

x<6
This means that on your graph at 6 it's a circle (not colored in) and it goes to the left indefinitely...
Thus, your answer.
X=25 ...... ................