Aline with a slope of 1/8 passes through the points (u, -9) and (6, -8). what is the value of u?

u = -2

Explanation:
Slope of the line can be calculated using the following rule:
slope = (y2-y1) / (x2-x1)

We are given :
slope = 1/8
point (u,-9) represent (x1,y1)
point (6,-8) represent (x2,y2)

Substitute with the givens in the above equation and solve for u as follows:
slope = (y2-y1) / (x2-x1)
1/8 = (-8--9) / (6-u)
1/8 = (1) / (6-u)
1* (6-u) = 1*8
6-u = 8
u = 6-8
u = -2

Hope this helps :)

What the proper work

The answer simplified would be. -6300x