If x2 = 20, what is the value of x?

Question and answers are in the attached picture. you so much in advance.

Find the sum of 4x^{2} -4+6 and -7^{2} +3x+1

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0