Help quick willl mrK you pints

Can someone with this? ! the answer choices are 1, 1.3, 1.45, and 1.9!

Aclothing store has the sign shown in the shop window. pani sees the sign and wants to buy 3 shirts and 2 pairs of jeans. the cost of each shirt before the discount is $12, and the cost of each pair of jeans is $19 before the discount. write and simplify an expression to find the amount pani pays if a $3 discount is applied to her total

What is always true when two whole numbers are subtracted?