7r^2-6=477

Solution for 7r^2-6=477 equation:

7r^2-6=477

We move all terms to the left:

7r^2-6-(477)=0

We add all the numbers together, and all the variables

7r^2-483=0

a = 7; b = 0; c = -483;
Δ = b2-4ac
Δ = 02-4·7·(-483)
Δ = 13524
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{13524}=\sqrt{196*69}=\sqrt{196}*\sqrt{69}=14\sqrt{69}$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-14\sqrt{69}}{2*7}=\frac{0-14\sqrt{69}}{14}
=-\frac{14\sqrt{69}}{14}
=-\sqrt{69}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+14\sqrt{69}}{2*7}=\frac{0+14\sqrt{69}}{14}
=\frac{14\sqrt{69}}{14}
=\sqrt{69}
$