How can i solve this exercise
6x + 2y = 2
-6x - 2y = 8

Sal is tiling his entryway. the floor plan is drawn on a unit grid. each unit length represents 1 foot. tile costs $1.35 per square foot. how much will sal pay to tile his entryway? round your answer to the nearest cent.

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

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