Please help me find the slope.

What values of x satisfy the inequality x^2-9x< 0? how is your answer shown on the graph?

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?

Find the length of the normal and the angle it makes with the positive x-axis. (see pictured below)