Question

How do you solve `x^2 + 5x - 1 = 0`?

Answer 1

Use the standard formula `x = (-b +- sqrt(b^2 - 4ac))/(2a)` to solve an expression `ax^2 + bx + c = 0`

Explanation:

In this case `x =( -5 +- sqrt(5^2 -4*1*(-1)))/(2*1)`
`x =( -5 +- sqrt(25 +4))/2`
`x = (-5 +- sqrt(29))/2`
`x=(-5+sqrt(29))/2 or (-5-sqrt(29))/2`
Using a calculator gives
`x=-5+5.385` or `x=-5-5.385`
`x=0.385` or `x=-10.385`