256r^2-169=0

Solution for 256r^2-169=0 equation:

256r^2-169=0

a = 256; b = 0; c = -169;
Δ = b2-4ac
Δ = 02-4·256·(-169)
Δ = 173056
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{173056}=416$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-416}{2*256}=\frac{-416}{512}
=-13/16
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+416}{2*256}=\frac{416}{512}
=13/16
$