Question

Solve the equation 2x²-x-8=0 ​

Answer 1

`x=(-1+-√(65))/(4)`

Explanation:

Using the quadratic formula,

`x=\frac{-b+-\sqrt{b^(2)-4ac}}{2a}\\x=\frac{-1+-\sqrt{-1^(2)+64}}{4}\\x=(1+-√(65))/(4)\\`

Answer 2

`= x_(1) = (1 - √(65) )/(4) . x_(2) = (1 + √(65) )/(4)`

Explanation:

`2x ^(2) - x - 8 = 0`

`x = \frac{ - ( - 1)± \sqrt{( - 1 {)}^(2) } - 4 * 2 * ( - 8)}{2 * 2}`

`x = (1± √(1 + 64) )/(4)`

`x = (1± √(65) )/(4)`

`= x_(1) = (1 - √(65) )/(4) . x_(2) = (1 + √(65) )/(4)`