2x*9x=91

Solution for 2x*9x=91 equation:

2x*9x=91

We move all terms to the left:

2x*9x-(91)=0

Wy multiply elements

18x^2-91=0

a = 18; b = 0; c = -91;
Δ = b2-4ac
Δ = 02-4·18·(-91)
Δ = 6552
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:

$\sqrt{\Delta}=\sqrt{6552}=\sqrt{36*182}=\sqrt{36}*\sqrt{182}=6\sqrt{182}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-6\sqrt{182}}{2*18}=\frac{0-6\sqrt{182}}{36}
=-\frac{6\sqrt{182}}{36}
=-\frac{\sqrt{182}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+6\sqrt{182}}{2*18}=\frac{0+6\sqrt{182}}{36}
=\frac{6\sqrt{182}}{36}
=\frac{\sqrt{182}}{6}
$