(7x)^2=196

Solution for (7x)^2=196 equation:

(7x)^2=196

We move all terms to the left:

(7x)^2-(196)=0

a = 7; b = 0; c = -196;
Δ = b2-4ac
Δ = 02-4·7·(-196)
Δ = 5488
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{5488}=\sqrt{784*7}=\sqrt{784}*\sqrt{7}=28\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-28\sqrt{7}}{2*7}=\frac{0-28\sqrt{7}}{14}
=-\frac{28\sqrt{7}}{14}
=-2\sqrt{7}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+28\sqrt{7}}{2*7}=\frac{0+28\sqrt{7}}{14}
=\frac{28\sqrt{7}}{14}
=2\sqrt{7}
$