How to transfer a decimal to a fraction or mixed number?

Solve by any method (graphing, substitution or linear combination)y = x - 82x + 3y = 1a) (2, -6)b) (5, -3)c) (4, -4)d) (0, -8)i figured it out. the answer is (5, -3)

Ineed here’s a picture of the question

Robert is placing sod in two square shaped areas of his backyard. one side of the first area is 7.5 feet. one side of the other area is 5.7 feet. the sod costs y dollars per square foot