Need help ASAP have a timed quiz and I don't understand the last question

Me solve this problem, and someone clearly explain to me how to solve it.1.) use the value of the discriminant to determine if the given trinomials has 2 real solutions, 1 real solution, or no real solutions. a.  x2  − 4x  − 7 = 0b. 4r2  + 11r  − 3 = 0c. 3m2  + 7 = 0d.  t2  + 2t  + 1 = 0

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

The tile along the edge of a triangular community pool needs to be replaced? ?