Lana's height is 2 inches tall less than her brother's height. Her brother's height her brother's height is unknown. Which expression shows Lana's height use x for her brother's height. A. x - 2
B. x/2
C. x + 2
D. 2x

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