Final answer:
The value of x is 7.
Step-by-step explanation:
The points (2,7) and (2, x) lie on the same line. If the slope of the line is 3, we can use the slope formula to find the value of x.
The slope formula is given by: m = (y2 - y1) / (x2 - x1)
Using the points (2,7) and (2, x), we have: 3 = (x - 7) / (2 - 2)
Since the denominator is 0, the slope is undefined and the line is vertical. This means that the x-coordinate of both points must be the same. Therefore, the value of x is 7.