Hey, could someone please solve the following two questions. With all steps and not too complexThank you...

6. You spend $48 on pizzas for a backyard get-together, expecting everyone to contribute equally to the cost. Two people show up that you didn't expect, resulting in each person contributing $2 less than you thought. How many people were initially meant to attend the get-together? [5] 7. For a quadratic function f (x) = ax? + bx + c, the interval of increase is x E (-co, 2), the interval of decrease is x E (2, co), and the x-intercepts are at - 3 and 7. Explain how you would use this information to determine the intervals of increase and decrease of y = [4]