Question

Solve 2x^2+3x-1=0 by completing the square

Answer 1

x=(-3-√17)/4

x=(-3+√17)/4

Explanation:

2x^2+3x-1=0

it can rewrite as,

x^2+3x/2-1/2=0

now adding and subtracting (3/4)^2 , in R.H.S,

x^2+3x/2+9/16-9/16-1/2=0

(x+3/4)^2-17/16=0

(x+3/4)^2-((√17)/4)^2=0

(x+3/4+√17/4)(x+3/4-√17/4)=0

x=(-3-√17)/4

x=(-3+√17)/4