Answer:
x = 1.5 (or as the fraction 3/2)
Explanation:
For this question, it is asking you to substitute numbers as variables using the coordinate pair given. (Important:) When looking at coordinates, the left number inside the parenthesis is the x-coordinate (? in this case), and the number in the parenthesis on the right is the y-coordinate (-4 in this case).
With that being said, this equation is basically asking us to solve for x. Now that we know this we can solve. Substitute y for -4:
4x - 3(-4) = 18
4x - (-12) = 18
When a negative sign is in front of a negative number, it becomes a positive number.
4x + 12 = 18
Now we can solve this problem using the proper formula. Subtract 12 from both sides of the equation to cancel out the +12:
4x + 12 = 18
- 12 -12
4x = 6
Now we need to single out the x in order to solve:
4x = 6
4 4
x = 1.5 (or simplified as the fraction 3/2)
Let me know if you need any more help with this topic, I hope that this helps.