Final answer:
To find the value of x in the equation y = 9 + 3x, we can use the given information that the line passes through the points (x,2) and (7,9) with a slope of 7/3. By using the slope formula, we can solve for x and find that x is approximately -1.56.
Step-by-step explanation:
To find the value of x in the equation y = 9 + 3x, we can use the given information that the line passes through the points (x,2) and (7,9) with a slope of 7/3. The slope of a line can be found using the formula m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are the coordinates of two points on the line. So, we can plug in the values (7,9) and (x,2) into the formula and solve for x:
7/3 = (2 - 9) / (x - 7)
Now, cross multiplying and simplifying the equation:
21 = 7 - 9x
9x = -14
x = -14/9
Therefore, the value of x is approximately -1.56.