Solve (x-3y)+(x-y)+(x+y)+(x+3y)=72

$$(x-3y)+(x-y)+(x+y)+(x+3y)=72$$

Solve for x

$$x=18$$

Steps for Solving Linear Equation

Combine x and x to get 2x.

$$2x-3y-y+x+y+x+3y=72$$

Combine -3y and -y to get -4y.

$$2x-4y+x+y+x+3y=72$$

Combine 2x and x to get 3x.

$$3x-4y+y+x+3y=72$$

Combine -4y and y to get -3y.

$$3x-3y+x+3y=72$$

Combine 3x and x to get 4x.

$$4x-3y+3y=72$$

Combine -3y and 3y to get 0.

$$4x=72$$

Divide both sides by 4.

$$x=\frac{72}{4}$$

Divide 72 by 4 to get 18.

$$x=18$$

Solve for y (complex solution)

$$y\in \mathrm{C}$$

$$x=18$$

Solve for y

$$y\in \mathrm{R}$$

$$x=18$$