Solve 4x^2-y-9=0

$$4 x ^ { 2 } - y - 9 = 0$$

Solve for y

$$y=4x^{2}-9$$

Steps for Solving Linear Equation

Subtract 4x^{2} from both sides. Anything subtracted from zero gives its negation.

$$-y-9=-4x^{2}$$

Add 9 to both sides.

$$-y=-4x^{2}+9$$

The equation is in standard form.

$$-y=9-4x^{2}$$

Divide both sides by -1.

$$\frac{-y}{-1}=\frac{9-4x^{2}}{-1}$$

Dividing by -1 undoes the multiplication by -1.

$$y=\frac{9-4x^{2}}{-1}$$

Divide -4x^{2}+9 by -1.

$$y=4x^{2}-9$$

Solve for x (complex solution)

$$x=-\frac{\sqrt{y+9}}{2}$$

$$x=\frac{\sqrt{y+9}}{2}$$

Solve for x

$$x=\frac{\sqrt{y+9}}{2}$$

$$x=-\frac{\sqrt{y+9}}{2}\text{, }y\geq -9$$