25u^2-35=0

Solution for 25u^2-35=0 equation:

25u^2-35=0

a = 25; b = 0; c = -35;
Δ = b2-4ac
Δ = 02-4·25·(-35)
Δ = 3500
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{3500}=\sqrt{100*35}=\sqrt{100}*\sqrt{35}=10\sqrt{35}$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-10\sqrt{35}}{2*25}=\frac{0-10\sqrt{35}}{50}
=-\frac{10\sqrt{35}}{50}
=-\frac{\sqrt{35}}{5}
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+10\sqrt{35}}{2*25}=\frac{0+10\sqrt{35}}{50}
=\frac{10\sqrt{35}}{50}
=\frac{\sqrt{35}}{5}
$