Solve y=2a^2-b

$$y = 2 a ^ { 2 } - b$$

Solve for b

$$b=2a^{2}-y$$

Steps for Solving Linear Equation

Swap sides so that all variable terms are on the left hand side.

$$2a^{2}-b=y$$

Subtract 2a^{2} from both sides.

$$-b=y-2a^{2}$$

Divide both sides by -1.

$$\frac{-b}{-1}=\frac{y-2a^{2}}{-1}$$

Dividing by -1 undoes the multiplication by -1.

$$b=\frac{y-2a^{2}}{-1}$$

Divide y-2a^{2} by -1.

$$b=-\left(y-2a^{2}\right)$$

Solve for a (complex solution)

$$a=-\frac{\sqrt{2\left(y+b\right)}}{2}$$

$$a=\frac{\sqrt{2\left(y+b\right)}}{2}$$

Solve for a

$$a=\frac{\sqrt{2\left(y+b\right)}}{2}$$

$$a=-\frac{\sqrt{2\left(y+b\right)}}{2}\text{, }y\geq -b$$