(16+9)(9)=3x^2

Solution for (16+9)(9)=3x^2 equation:

(16+9)(9)=3x^2

We move all terms to the left:

(16+9)(9)-(3x^2)=0

We add all the numbers together, and all the variables

-3x^2+259=0

a = -3; b = 0; c = +259;
Δ = b2-4ac
Δ = 02-4·(-3)·259
Δ = 3108
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:

$\sqrt{\Delta}=\sqrt{3108}=\sqrt{4*777}=\sqrt{4}*\sqrt{777}=2\sqrt{777}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{777}}{2*-3}=\frac{0-2\sqrt{777}}{-6}
=-\frac{2\sqrt{777}}{-6}
=-\frac{\sqrt{777}}{-3}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{777}}{2*-3}=\frac{0+2\sqrt{777}}{-6}
=\frac{2\sqrt{777}}{-6}
=\frac{\sqrt{777}}{-3}
$