Multiplying ,you get 18x^2+21x-24x-28. You simplify to get:
18x^2-3x-28.
The inverse is f¯¹(x)=x/7.
We have to find the GCD between 10, 16 and 4 and between x^5, x^4 and x^2
GCD (10,16,4) = 2
GCD (x^5,x^4,x^2) = x^2
So we divide all terms for 2x^2
Final result: 2x^2(5x^3-8x^2+2)
First you would do $325.49 divided by 10 and you would get $32.55. so you would need $32.55 a week.
