Question

What are the solution(s) to the quadratic equation 40 - x2 = 0?

Answer 1

Step-by-step explanation:

$40 - {x}^{2} = 0 \\ \therefore \: {x}^{2} = 40 \\ \therefore \: x = \pm \sqrt{40} \\ \therefore \: x = \pm \sqrt{4 \times 10} \\ \huge \red{ \boxed{\therefore \: x = \pm 2\sqrt{10}}}$

Answer 2

Start with

$40-x^2=0$

Add $x^2$ to both sides:

$x^2=40$

Take the square root of both sides:

$x=\pm\sqrt{40}=\pm\sqrt{4\cdot 10}=\pm 2\sqrt{10}$