What kind of quadrilateral is this shaoe

What is the missing step in this proof ?

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items

Kayla has a $500 budget for the school party. she paid $150 for the decorations. food will cost $5.50 per student. what inequality represents the number of students, s, that can attend the party?