Solve 3y-9y--15y+8y+-20y--12=15

$$3 y - 9 y - - 15 y + 8 y + - 20 y - - 12 = 15$$

Solve for y

$$y=-1$$

Steps for Solving Linear Equation

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

$$-6y-\left(-15y\right)+8y-20y-\left(-12\right)=15$$

The opposite of -15y is 15y.

$$-6y+15y+8y-20y-\left(-12\right)=15$$

Combine -6y and 15y to get 9y.

$$9y+8y-20y-\left(-12\right)=15$$

Combine 9y and 8y to get 17y.

$$17y-20y-\left(-12\right)=15$$

Combine 17y and -20y to get -3y.

$$-3y-\left(-12\right)=15$$

The opposite of -12 is 12.

$$-3y+12=15$$

Subtract 12 from both sides.

$$-3y=15-12$$

Subtract 12 from 15 to get 3.

$$-3y=3$$

Divide both sides by -3.

$$y=\frac{3}{-3}$$

Divide 3 by -3 to get -1.

$$y=-1$$