Can somebody please help me with these problems? I have the answer for 2 or 3 but my friend and I need to check our answers. I’ll give you brainliest if you want!! Plus I put 100 points so there should be a lot of points

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

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?

Ireally need subtract and simplify.(-y^2 – 4y - 8) – (-4y^2 – 6y + 3)show your work, ! i will mark you brainliest but you have to show your work.