Whats the relationship of indicated angles, what do we know and solving x?

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

Which value of m will create a system of parallel lines with no solution? y= mx - 6 8x - 4y = 12

What expression is equivalent to (84+16)