Help me pls i don't understand the problem so can u give me the answers and also explain

Find the domain and range of the following function f(x) = 51x - 21+ 4

A50-foot ladder is leaning against a vertical wall. if the base of the ladder is 45 feet from the base of the wall, find the angle the bottling of the ladder makes with the ground.

Triangles abd and ace are similar right triangles. witch ratio best explains why the slope of ab is the same as the slope of ac?