Solve xy-9x-9y=20

$$x y - 9 x - 9 y = 20$$

Solve for x

$$x=\frac{9y+20}{y-9}$$

$$y\neq 9$$

Steps for Solving Linear Equation

Add 9y to both sides.

$$xy-9x=20+9y$$

Combine all terms containing x.

$$\left(y-9\right)x=20+9y$$

The equation is in standard form.

$$\left(y-9\right)x=9y+20$$

Divide both sides by y-9.

$$\frac{\left(y-9\right)x}{y-9}=\frac{9y+20}{y-9}$$

Dividing by y-9 undoes the multiplication by y-9.

$$x=\frac{9y+20}{y-9}$$

Solve for y

$$y=\frac{9x+20}{x-9}$$

$$x\neq 9$$

Steps for Solving Linear Equation

Add 9x to both sides.

$$xy-9y=20+9x$$

Combine all terms containing y.

$$\left(x-9\right)y=20+9x$$

The equation is in standard form.

$$\left(x-9\right)y=9x+20$$

Divide both sides by x-9.

$$\frac{\left(x-9\right)y}{x-9}=\frac{9x+20}{x-9}$$

Dividing by x-9 undoes the multiplication by x-9.

$$y=\frac{9x+20}{x-9}$$