5x^2-8x-4=0 solve using quadratic formula

Question

I know the answer is -2/5, 2 but I can not write it out with that number. can you help me see the steps. thank you

Answer 1

Roseland,

                Complete the square and the roots are (4/5) -(2/5)i and (4/5)+(2/5)i where i=√-1

 

Jim