Solve 2x^2-40x+2400-c=0

$$2 x ^ { 2 } - 40 x + 2400 - c = 0$$

Solve for c

$$c=2\left(x^{2}-20x+1200\right)$$

Steps for Solving Linear Equation

Subtract 2x^{2} from both sides. Anything subtracted from zero gives its negation.

$$-40x+2400-c=-2x^{2}$$

Add 40x to both sides.

$$2400-c=-2x^{2}+40x$$

Subtract 2400 from both sides.

$$-c=-2x^{2}+40x-2400$$

Divide both sides by -1.

$$\frac{-c}{-1}=\frac{-2x^{2}+40x-2400}{-1}$$

Dividing by -1 undoes the multiplication by -1.

$$c=\frac{-2x^{2}+40x-2400}{-1}$$

Divide -2x^{2}+40x-2400 by -1.

$$c=2x^{2}-40x+2400$$

Solve for x (complex solution)

$$x=\frac{\sqrt{2c-4400}}{2}+10$$

$$x=-\frac{\sqrt{2c-4400}}{2}+10$$

Solve for x

$$x=\frac{\sqrt{2c-4400}}{2}+10$$

$$x=-\frac{\sqrt{2c-4400}}{2}+10\text{, }c\geq 2200$$