Answer:
x= 1/5 or -2
Explanation:
5x² +11x +2= 0
(Divide through by the coefficient of x²)
5x²/5 + 11x/5 + 2/5 = 0/5
x² + 11x/5 + 2/5 = 0
(take the constant to the other side)
x² + 11x/5 = -2/5
(Add 1/2 of the coefficisint of x all square to both sides)
x² + x + (11/5 × 1/2)² = -2/5 + (11/5 × 1/2)²
x² + x + (11/10)² = -2/5 + (11/10)²
x² + x + (11/10)² = -2/5 + 121/100
(eliminate x )
x² + (11/10)² = (20(-2) + 121 ) ÷ 100
(x + 11/10 )² = (-40 + 121) ÷ 100
(x + 11/10 )² = 81/100
(square both sides)
x + 11/ 10 =√(81/100)
x + 11/10 = 9/10
x = -11/10 +or- 9/10
x = -11/10 + 9/10 or -11/10 - 9/10
x = (-11 + 9) ÷ 10 or (-11-9) ÷ 10
x = -2/ 10 or -20/10
x = -1/5 or -2