-672=c^2-2c(28.25)

Solution for -672=c^2-2c(28.25) equation:

-672=c^2-2c(28.25)

We move all terms to the left:

-672-(c^2-2c(28.25))=0


We calculate terms in parentheses: -(c^2-2c(28.25)), so:

c^2-2c(28.25)

We multiply parentheses

c^2-56.5c

Back to the equation:

-(c^2-56.5c)


We get rid of parentheses

-c^2+56.5c-672=0

We add all the numbers together, and all the variables

-1c^2+56.5c-672=0

a = -1; b = 56.5; c = -672;
Δ = b2-4ac
Δ = 56.52-4·(-1)·(-672)
Δ = 504.25
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{-(56.5)-\sqrt{504.25}}{2*-1}=\frac{-56.5-\sqrt{504.25}}{-2}
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(56.5)+\sqrt{504.25}}{2*-1}=\frac{-56.5+\sqrt{504.25}}{-2}
$