I got stumped and need help answering the last 3 questions on this page.

If x=-3 is the only x-intercept of the graph of a quadratic equation, which statement best discribes the discriminant of the equation?

Answer asap ! the shortest path from point a to point b goes through a pond. to avoid the pond, you must walk straight 34 meters along one edge of the pond, then take a 90 degree turn, and again walk straight 41 meters along another edge of the pond to reach point b. about how many meters would be saved if it were possible to walk through the pond? a. 11 m b. 20 m c. 30.45 m d. 21.73 m

Which radical expression is a rational number? a. √ 360 b. √ 644 c. √ 225 d. √ 122