What should be added to 4/5 to get -3/2

Can someone check if i did this correct. it’s number 4 if you’re wondering.

Samantha is growing a garden in her back yard. she spend $90 setting up the garden bed and buying the proper garden supplies. in addition, each seed she plants cost $0.25. a. write the function f(x) that represents samantha's total cost on her garden. b. explain what x represents. c. explain what f(x) represents. d. if samantha plants 55 seeds, how much did she spend in total?

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