Find the domain : 15 - sq root (x+2)

Which expression is not a polynomial?

The path traveled by a bottlenose dolphin as it jumps out of water is modeled by the equation y=-0.4+3x, where t is the height above water and x is the horizontal distance in feet. if a beam of light is shone upward at an angle modeled by the equation x+y=10, at what height from the waters surface will the beam of light hit the dolphin

Leo takes 30 minutes to eat dinner, 15 minutes to change clothes, and 20 minutes to walk to practice.if leo needs to be at hockey practice at 7: 15pm,.what time does he need to begin