5w^2-140=0

Solution for 5w^2-140=0 equation:

5w^2-140=0

a = 5; b = 0; c = -140;
Δ = b2-4ac
Δ = 02-4·5·(-140)
Δ = 2800
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2800}=\sqrt{400*7}=\sqrt{400}*\sqrt{7}=20\sqrt{7}$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-20\sqrt{7}}{2*5}=\frac{0-20\sqrt{7}}{10}
=-\frac{20\sqrt{7}}{10}
=-2\sqrt{7}
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+20\sqrt{7}}{2*5}=\frac{0+20\sqrt{7}}{10}
=\frac{20\sqrt{7}}{10}
=2\sqrt{7}
$