The product of two different squares is always a perfect square

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?

If private savings 'v' = 0.75s and total savings 's' equals $4.20 billion, solve for public and private savings.

Having a hard time understanding this question (see attachment).