5v^2-30v-70=0

Solution for 5v^2-30v-70=0 equation:

5v^2-30v-70=0

a = 5; b = -30; c = -70;
Δ = b2-4ac
Δ = -302-4·5·(-70)
Δ = 2300
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2300}=\sqrt{100*23}=\sqrt{100}*\sqrt{23}=10\sqrt{23}$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-10\sqrt{23}}{2*5}=\frac{30-10\sqrt{23}}{10}
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+10\sqrt{23}}{2*5}=\frac{30+10\sqrt{23}}{10}
$