13x*9x=220

Solution for 13x*9x=220 equation:

13x*9x=220

We move all terms to the left:

13x*9x-(220)=0

Wy multiply elements

117x^2-220=0

a = 117; b = 0; c = -220;
Δ = b2-4ac
Δ = 02-4·117·(-220)
Δ = 102960
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:

$\sqrt{\Delta}=\sqrt{102960}=\sqrt{144*715}=\sqrt{144}*\sqrt{715}=12\sqrt{715}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12\sqrt{715}}{2*117}=\frac{0-12\sqrt{715}}{234}
=-\frac{12\sqrt{715}}{234}
=-\frac{2\sqrt{715}}{39}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12\sqrt{715}}{2*117}=\frac{0+12\sqrt{715}}{234}
=\frac{12\sqrt{715}}{234}
=\frac{2\sqrt{715}}{39}
$