C=0.6p^2-7.2p+4

Solution for C=0.6p^2-7.2p+4 equation:

=0.6C^2-7.2C+4

We move all terms to the left:

-(0.6C^2-7.2C+4)=0

We get rid of parentheses

-0.6C^2+7.2C-4=0

a = -0.6; b = 7.2; c = -4;
Δ = b2-4ac
Δ = 7.22-4·(-0.6)·(-4)
Δ = 42.24
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{-(7.2)-\sqrt{42.24}}{2*-0.6}=\frac{-7.2-\sqrt{42.24}}{-1.2}
$
$C_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7.2)+\sqrt{42.24}}{2*-0.6}=\frac{-7.2+\sqrt{42.24}}{-1.2}
$