i can give you the exact answer to your question, but what are the equations for the companies and how much do the edwards have to spend? if not, here's how to do it:
y= m(225)+b for each company. i used slope-intercept form assuming that's what form the equations are written in. it's basically saying x=225 in part a (look for the lowest y) and in part b y≥m(225)+b (look for which company's equation makes the statement true)
(ps i'm checking every few minutes if you want to comment and get the exact answer)