Divide through by 5
5/5 x^2 + 13/5 x - 6/5 = 0/5
Which gives
X^2 + 13/5 x - 6/5 = 0
Move constant to right
X^2 + 13/5 x = 6/5
Take half of x term and square it
(13/5 * 1/2)^2 = 169/100
Add to both sides
X^2 + 13/5 x+ 169/100 = 6/5 +169/100
(X +13/10)^2 = 289/100
Root both sides
X + 13/10 = +- root(289/100)
Simplify
X + 13/10 = +- 17/10
X= -13/10 +- 17/10
Therefore
X = -13/10 +17/10
Or
X = -13/10 - 17/10
Which becomes
X=0.4 and x=-3
Hope this helps
