How do you do this. Help me please. It’s number 9 and 10

Janet drove 300 miles in 4.5 hours. write an equation to find the rate at which she was traveling

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.