Question
$x^2 + 4x – 5 = 0, x = 1, -1$
✓
Answer
$x^2+4 x-5=0$
Put $x =1$
$\Rightarrow 1^2+4 \times 1-5 $
$\Rightarrow 1+4-5=0$
Put $x =-1$
$\Rightarrow(-1)^2+4(-1)-5 $
$\Rightarrow 1-4-5=-8$
$\therefore x =1$ is a root of the equation and $x =-1$ is not a root of the equation.
Put $x =1$
$\Rightarrow 1^2+4 \times 1-5 $
$\Rightarrow 1+4-5=0$
Put $x =-1$
$\Rightarrow(-1)^2+4(-1)-5 $
$\Rightarrow 1-4-5=-8$
$\therefore x =1$ is a root of the equation and $x =-1$ is not a root of the equation.
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