Question

Solve the quadratic equation 5x2 - 125 = 0.

Answer 1

Let's solve this with the quadratic formula, which is: $x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$
Let's plug in the values:
$\frac{-0+\sqrt{0^2-4\cdot \:5\left(-125\right)}}{2\cdot \:5}$
Remove exponents:
$=\frac{-0+\sqrt{0-\left(-125\right)\cdot \:4\cdot \:5}}{2\cdot \:5}$
Simplify.
$=\frac{-0+\sqrt{0-\left(-125\right)\cdot \:4\cdot \:5}}{10}$
$=\frac{\sqrt{-\left(-125\right)\cdot \:20}}{10}$
$=\frac{50}{10}$
$=\pm 5$

This leaves us with the final solutions being:
$x=5,\:x=-5$

Let me know if you have any questions regarding this problem!
Thanks!
-TetraFish