Simplify (3n – 2m)^2 = ?

a). 9n^2 + 12mn + 4m^2
b.) 9n^2 - 12mn - 4m^2
c.) 9n^2 - 12mn + 4m^2
d.) 6n^2 - 12mn -4m^2

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