Question

If using the method of completing the square to solve the quadratic equation x^2 - 9x - 8 = 0, which number would have to be added to "complete the square"

Answer 1

Number: 28.25

Solution to Quadratic:
`x=(9)/(2)\pm(√(113))/(2)}`

Explanation:

`x^2-9x-8=0`

`x^2-9x-8+28.25=0+28.25` <-- 28.25 is the number you need to add

`x^2-9x+20.25=28.25`

`(x-4.5)^2=28.25`

`x-4.5=\pm√(28.25)`

`x=4.5\pm√(28.25)`

`x=(9)/(2)\pm\sqrt{(113)/(4)}`

`x=(9)/(2)\pm(√(113))/(2)}`