471=6*r2*3.14

Solution for 471=6*r2*3.14 equation:

471=6r^2*3.14

We move all terms to the left:

471-(6r^2*3.14)=0

We get rid of parentheses

-6r^2*3.14+471=0

Wy multiply elements

-18.84r^2+471=0

a = -18.84; b = 0; c = +471;
Δ = b2-4ac
Δ = 02-4·(-18.84)·471
Δ = 35494.56
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{35494.56}}{2*-18.84}=\frac{0-\sqrt{35494.56}}{-37.68}
=-\frac{\sqrt{}}{-37.68}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{35494.56}}{2*-18.84}=\frac{0+\sqrt{35494.56}}{-37.68}
=\frac{\sqrt{}}{-37.68}
$