Ls help on this question

Pls

A20? -foot ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 19 feet from the base of the building. how high up the wall does the ladder? reach?

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

Write the rational number in lowest terms 99/-15