6th grade please help!

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?

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

Convert 4 3/5 cups to pints if 2 cups equals 1 pint