Simplify 45/63 show work plz

How do i solve using pythagorean theorem?

The graph of which of the following will be parallel to the graph of 4x – 3y = –12? a.y= 4/3x -3/2 b.6x-4y=-8 c. y=3/4x+1 d.4x- 2y=-12

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.