(6,-5) (7,-3) (8,-1) (9,1) is this a function?

What should be done to solve the equation? x+14=21 add 14 to both sides of the equation. subtract 14 from the left side of the equation. add 14 to the left side and subtract 14 from the right side of the equation. subtract 14 from both sides of the equation.

How many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

Thelime contains the point(-3,0) and parallel x-3y=3( show all work)