Question

Using the quadratic formula to solve x2 = 5 – x, what are the values of x?

Answer 1

`(-1+√(21))/(2)` and
`(-1-√(21))/(2)`.

Explanation:

The given quadratic equation is

`x^2=5-x`

It is can written as

`x^2+x-5=0`

If a quadratic equation is
`ax^2+bx+c=0`, then the quadratic formula is

`x=(-b\pm √(b^2-4ac))/(2a)`

In the given quadratic equation
`a=1,b=1,c=-5`. So,

`x=(-1\pm √(1^2-4(1)(-5)))/(2(1))`

`x=(-1\pm √(1+20))/(2)`

`x=(-1\pm √(21))/(2)`

`x=(-1+√(21))/(2),(-1-√(21))/(2)`

Therefore, the values of x are
`(-1+√(21))/(2)` and
`(-1-√(21))/(2)`.