I didn’t understand this my teacher said there’s definitely a answer amongst these so get this right I will offer brainalist + 10 points

The $x$-intercepts of the parabola $y = x^2 + bx + c$ are $(-3,0)$ and $(5,0).$ find the equation of the parabola, and submit your answer in $y = ax^2 + bx + c$ form.

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?

Sara can take no more than 22 pounds of luggage on a trip.her suitcase weighs 112 ounces.how many more pounds can she pack without going over the limit?