Is a triangle with the lengths 12, 9, 15 a right triangle

Marya wants to factor the polynomial 36x^3 -22x^2 - 144x.which term can she add to the polynomial that would not change its grestest common factor? check all that apply

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

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