How to find the inverse of g(x) = -3 +(3/5)x

I’ve been trying all day to figure this puzzle out. i need the work for it aswell. it is a factoring polynomials tarsia. the image is below.

Which unit rate is the lowest price per ounce? (5 points) choice a: 6 ounces of chocolate chips for $2.49 choice b: 8 ounces of chocolate chips for $3.32

Shannon mary and john earn a weekly allowance ahannon earns the amount that is 2/3 of what john earns mary earns an amount that is 1 2/3 of what johns earns 20 dollars a week who eaens the greatest allowance and who earns the least