A retail store has two options for discounting items to go on clearance. 1: Decrease the price of the item by 15% each week.
2: Decrease the price of the item by $5 each week. If the cost of an item is $45, write a function rule for the difference in price between the two options.

Difference = 1.75 , Function = mod [ 0.15x - 5 ]

Explanation:

Discount case 1 = $5 {Each week} , Discount case 2 = 15% {Each week}

After 1st week , for item cost = 45

Difference in price = 40 - 38.25 = 1.75  .It is same is difference in discount = 6.75 - 5 , ie = 1.75

Functional rule in price difference , for item with unknown price 'x' =          mod [ (x - 5) - (x - 0.15x) ] = mod [ x - 5 - x + 0.15x ] =  mod [ 0.15x - 5 ] , which is same as difference between discount '0.15x & 5'