r*r=196

Solution for r*r=196 equation:

r*r=196

We move all terms to the left:

r*r-(196)=0

Wy multiply elements

r^2-196=0

a = 1; b = 0; c = -196;
Δ = b2-4ac
Δ = 02-4·1·(-196)
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-28}{2*1}=\frac{-28}{2}
=-14
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+28}{2*1}=\frac{28}{2}
=14
$