I don't know what sex is

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

With finding limits of multi variable !

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.