Question 332156
{{{x^2 + 4x - 5 = 0}}}
Complete the square
{{{x^2 + 4x + (4/2)^2 = 5 + (4/2)^2}}}
{{{x^2 + 4x + 4 = 5 + 4}}}
{{{(x + 2)^2 = 3^2}}}
{{{x + 2 = 3}}}
{{{x = 1}}}
and
{{{x + 2 = -3}}}
{{{x = -5}}}
The roots are 1 and -5
Here's a plot:
{{{ graph( 500, 500, -10, 5, -10, 10, x^2 + 4x - 5) }}}