How to find slope through pair of points? (-4,-,-2)

Tell me how you got the it use the figures to answer questions 1and 2. in each diagram, line k is parallel to line l, and line t intersects lines. 1. based on the diagrams, what is the value of x? 2. how would you verify your answer for x?

When you answer this can you explain

What value of x is in the solution set of 4x - 12 s 16 + 8x? -10 -9 -8 -7