i have four math problems i have been struggling with for a while now

Questions 1,2: using rational theorem + descartes's rule of sign to determine possible rational & real zeroes. find all zeroes & express the polynomial as a product of linear factors. sketch the graph of the function, indicating all intercepts. estimate turning points.

1. f(x) = 3x^3 + 2x^2 - 19x + 6

2. f(x) = X^4 - 3x^3 + 6x^2 - 12x + 8

Question 3: a company manufactures scooters and estimates profit depending on advertising expenses using the function: f(x) = -.25x^2 + 20x + 100

what expense in advertising will yield the maximum profit? what would the profit be?

Question 4: i could not past the graph on this problem i hope that does not cause any problems.

the graph above indicates the recent anticipated rise in global precipitation as greenhouse gases increase over time. selecting the coordinates (200,2) and (2050,4), write a linear function that would enable us to predict the % increase by 2150.

again it is greatly appreciated to all you are willing to help me with these four questions.