X=9
You add 3 to both sides which leaves you with 2x=18 and then divide by two and that gives you x=9
Answer:

Step-by-step explanation:
The line given has a slope of 7.5 and a point at (12, 80)
Because of the slope, simply subtract 2 from the x and subtract 15 from the y to get another point, at (10, 65)
Thus, simply put your points at (10, 65) and (12, 80)
Hope it helps and let me know if you want me to elaborate.