Solve D=-3x+4y+9x-15y-4x+2y

$$D = - 3 x + 4 y + 9 x - 15 y - 4 x + 2 y$$

Solve for D

$$D=2x-9y$$

Solution Steps

Combine -3x and 9x to get 6x.

$$D=6x+4y-15y-4x+2y$$

Combine 4y and -15y to get -11y.

$$D=6x-11y-4x+2y$$

Combine 6x and -4x to get 2x.

$$D=2x-11y+2y$$

Combine -11y and 2y to get -9y.

$$D=2x-9y$$

Solve for x

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

Steps for Solving Linear Equation

Combine -3x and 9x to get 6x.

$$D=6x+4y-15y-4x+2y$$

Combine 4y and -15y to get -11y.

$$D=6x-11y-4x+2y$$

Combine 6x and -4x to get 2x.

$$D=2x-11y+2y$$

Combine -11y and 2y to get -9y.

$$D=2x-9y$$

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

$$2x-9y=D$$

Add 9y to both sides.

$$2x=D+9y$$

The equation is in standard form.

$$2x=9y+D$$

Divide both sides by 2.

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

Dividing by 2 undoes the multiplication by 2.

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