Juie purchased a pair of Pants that originally cost $50. The pants were discounted 20% and sales tax is 5%, which expression would calculate the total cost of the pants?
1) 50 - (20% of 50) + (5% of (50 - (20% of 50)))
2) 50 + (20% of 50) + (5% of (50 + (20% of 50)))
3) 50 - (20% of 50) + (5% of 50)
4) 50 + (20% of 50) + (5% of 50)