Please help I have no idea how to do it

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

47: 4 aisha changed 1.45 + 2.38 to 1.5 + 2.4 in order to estimate the sum. what estimation method did she use?

What states a rule using variables expression term or formula