3(5-x)4x=18

Solution for 3(5-x)4x=18 equation:

3(5-x)4x=18

We move all terms to the left:

3(5-x)4x-(18)=0

We add all the numbers together, and all the variables

3(-1x+5)4x-18=0

We multiply parentheses

-12x^2+60x-18=0

a = -12; b = 60; c = -18;
Δ = b2-4ac
Δ = 602-4·(-12)·(-18)
Δ = 2736
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:

$\sqrt{\Delta}=\sqrt{2736}=\sqrt{144*19}=\sqrt{144}*\sqrt{19}=12\sqrt{19}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(60)-12\sqrt{19}}{2*-12}=\frac{-60-12\sqrt{19}}{-24}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(60)+12\sqrt{19}}{2*-12}=\frac{-60+12\sqrt{19}}{-24}
$