-16c+18-4c=9(-5c+18)3c

Solution for -16c+18-4c=9(-5c+18)3c equation:

-16c+18-4c=9(-5c+18)3c

We move all terms to the left:

-16c+18-4c-(9(-5c+18)3c)=0

We add all the numbers together, and all the variables

-20c-(9(-5c+18)3c)+18=0


We calculate terms in parentheses: -(9(-5c+18)3c), so:

9(-5c+18)3c

We multiply parentheses

-135c^2+486c

Back to the equation:

-(-135c^2+486c)


We get rid of parentheses

135c^2-486c-20c+18=0

We add all the numbers together, and all the variables

135c^2-506c+18=0

a = 135; b = -506; c = +18;
Δ = b2-4ac
Δ = -5062-4·135·18
Δ = 246316
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{246316}=\sqrt{4*61579}=\sqrt{4}*\sqrt{61579}=2\sqrt{61579}$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-506)-2\sqrt{61579}}{2*135}=\frac{506-2\sqrt{61579}}{270}
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-506)+2\sqrt{61579}}{2*135}=\frac{506+2\sqrt{61579}}{270}
$