$21.50×5 =107.50
107.50×.20=21.50
107.50-21.50=$86 for 5 days.
Cos28 = x/4 so to get rid of the fraction , multiply each side by 4 so it'll be
4cos28 = x
x = 3.531790371
Hope this helps=)
It’s 3 because you take the sum of all decreases (which is $9) and divide them by 3
