9c-c*c=2

Solution for 9c-c*c=2 equation:

9c-c*c=2

We move all terms to the left:

9c-c*c-(2)=0

Wy multiply elements

-1c^2+9c-2=0

a = -1; b = 9; c = -2;
Δ = b2-4ac
Δ = 92-4·(-1)·(-2)
Δ = 73
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-\sqrt{73}}{2*-1}=\frac{-9-\sqrt{73}}{-2}
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+\sqrt{73}}{2*-1}=\frac{-9+\sqrt{73}}{-2}
$