Solve 10x+y=x+10y+9

$$10 x + y = x + 10 y + 9$$

Solve for x

$$x=y+1$$

Steps for Solving Linear Equation

Subtract x from both sides.

$$10x+y-x=10y+9$$

Combine 10x and -x to get 9x.

$$9x+y=10y+9$$

Subtract y from both sides.

$$9x=10y+9-y$$

Combine 10y and -y to get 9y.

$$9x=9y+9$$

Divide both sides by 9.

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

Dividing by 9 undoes the multiplication by 9.

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

Divide 9+9y by 9.

$$x=y+1$$

Solve for y

$$y=x-1$$

Steps for Solving Linear Equation

Subtract 10y from both sides.

$$10x+y-10y=x+9$$

Combine y and -10y to get -9y.

$$10x-9y=x+9$$

Subtract 10x from both sides.

$$-9y=x+9-10x$$

Combine x and -10x to get -9x.

$$-9y=-9x+9$$

The equation is in standard form.

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

Divide both sides by -9.

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

Dividing by -9 undoes the multiplication by -9.

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

Divide -9x+9 by -9.

$$y=x-1$$