7x*12x=280

Solution for 7x*12x=280 equation:

7x*12x=280

We move all terms to the left:

7x*12x-(280)=0

Wy multiply elements

84x^2-280=0

a = 84; b = 0; c = -280;
Δ = b2-4ac
Δ = 02-4·84·(-280)
Δ = 94080
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:

$\sqrt{\Delta}=\sqrt{94080}=\sqrt{3136*30}=\sqrt{3136}*\sqrt{30}=56\sqrt{30}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-56\sqrt{30}}{2*84}=\frac{0-56\sqrt{30}}{168}
=-\frac{56\sqrt{30}}{168}
=-\frac{\sqrt{30}}{3}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+56\sqrt{30}}{2*84}=\frac{0+56\sqrt{30}}{168}
=\frac{56\sqrt{30}}{168}
=\frac{\sqrt{30}}{3}
$