Three simple math problems! Help!?

[ben z]

A rectangular painting has dimensions x and x + 10. The painting is in a frame 2 in wide. The total area of the picture and fram is 900 in^2. What are the dimensions of the painting?

A ball is thrown upward from a height of 15ft with an initial upward velocity of 5ft/s. Use the formula h = -16t^2 + vt + s to find out how long it will take for the ball to hit the ground.

You are placing a rectangular picture on a square poster board. You can enlarge the picture to any size. The area of the poster board not covered by the picture is modeled by the equation A = -x^2 - 10x + 300. Is it possible for the area not covered by the picture to be 100 in^2?
* I guessed no for this one. Too bad I need to show work!


Thanks in advance!