Question

How do you solve `x²-7x+4=0` using the quadratic formula?

Answer 1

`x = 7/2+-sqrt(33)/2`

Explanation:

`x^2-7x+4=0` is in the form `ax^2+bx+c=0` with `a=1`, `b=-7` and `c=4`.

This has roots given by the quadratic formula:

`x = (-b+-sqrt(b^2-4ac))/(2a)`

`=(7+-sqrt((-7)^2-(4*1*4)))/(2*1)`

`=(7+-sqrt(49-16))/2`

`=(7+-sqrt(33))/2`

`=7/2+-sqrt(33)/2`