I need a strategy and explain how it gets solved ?

How do you use the elimination method for this question? explain, because i really want to understand!

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0

Complete the input-output table for the linear function y = 3x. complete the input-output table for the linear function y = 3x. a = b = c =