-6v2+42v-36=0

Solution for -6v2+42v-36=0 equation:

-6v^2+42v-36=0

a = -6; b = 42; c = -36;
Δ = b2-4ac
Δ = 422-4·(-6)·(-36)
Δ = 900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{900}=30$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(42)-30}{2*-6}=\frac{-72}{-12}
=+6
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(42)+30}{2*-6}=\frac{-12}{-12}
=1
$