Determine the roots answer asap please

Question

determine the roots of the quadratic equation.(complete the square) express your answer in exact values.
5x2+20x-1=0

Answer 1

Add 1 to both sides and then divide both sides by 5:

 

x² + 4x = 1/5

 

Add 4 to both sides:

 

x² + 4x + 4 = 21/5

 

(x + 2)² = 21/5

 

x + 2 = ±√(21/5)

 

x = -2 ± √(21/5)

 

x = -2 ± √21/√5

 

x = (-2√5 ± √21)/√5

 

x = (-10 ± √105)/5