Ned help with this don't anwser if you don't know​

Clara schumann is buying bagels for her coworkers, she buys a dozen bagels priced at $5.49 a dozen. the bakery's cost for making the bagels is $2.25 per dozen. what is the markup rate based on selling price on a dozen bagels?

What is the slope-intercept form for each equation in this system? compare the slopes and y-intercepts to describe the graph of the system. 3x - 4y = 28 4x + 10y = 20

30 points if you answer all 3 questions with work!