Question

Solve:
$x^2-4x-5$

Answer 1

$x^2=4x-5$

By moving the constant to the right side

$x^2-4x=5$

Adding $4$ on both sides to create a perfect square trinomial to find the solution.

$x^2-4x+4=5+4$

$(x-2{)}^2=9as(x^2+2^2-2\ast 2x)=(x-2{)}^2$

$x-2=\sqrt{9}$

Taking the postive value

$=3$

$x=3+2$

$x=5$