Write the sum of 56+64 as the product of their gfc and another sum

The line y = x + passes through (−3, 7) and is parallel to y = 4x − 1.

I’m stuck on this equation, anyone got the answer?

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.