Please help me with geometry question

What is the solution to the system of the equations? x = y - 3 x + 3y = 13

Triangle xyz has vertices x(1,3), y(0,0)

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