Match each statement with the algebraic expression that models it.
a. the price of a winter coat and a 20% discount
1. x+0.02x=1.02x
b. the base salary of an employee and a 2% salary increase
2. x-0.20x=0.80x
c. the cost of groceries and a 2% discount with coupons
3. x+0.20x=1.20x
d. the number of students attending school last year
4. x-0.02x=0.98x
and a 20% increase from last year

Statement A: 

The price of a winter coat and a 20% discount
Let the price of the coat = x
20% discount = 20% of x = 0.20 × x = 0.20x
The price after the discount  = x - 0.20x = 0.80x

Statement B: 

Let the base salary be 'x'
2% increase = 2% of x = 0.02 × x = 0.02x
The salary after increase = x + 0.02x = 1.02x

Statement C:

Let the cost of groceries be 'x'
2% discount means 2% of x = 2% × x = 0.02x
The cost after discount = x - 0.02x = 0.98x

Statement D:

Let the number of students attending last year be 'x'
20% of x = 20% × x = 0.2x
The number after increase = x + 0.2x = 1.02x 

The pairs are

Statement A ⇒ Expression 2
Statement B ⇒ Expression 1
Statement C ⇒ Expression 4
Statement D ⇒ Expression 3