Someone please help me and thank you:)

What does independent variable and dependent variable mean in math?

Which equation represents a line that passes through the point (9, -4) and has a slope of 3/5?

An airplane is flying at an elevation of 5150 ft, directly above a straight highway. two motorists are driving cars on the highway on opposite sides of the plane, and the angle of depression to one car is 35 ̊ and to the other is 52 ̊. how far apart are the cars?