Help please its math and i dont knon how to solve them

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

If private savings 'v' = 0.75s and total savings 's' equals $4.20 billion, solve for public and private savings.

With alll of except for the 2 that i did already