Hey there Alex,
With a problem like that, you have to get the variable (in this case it is W) by itself.
Now W is being divided by 4-13 which is -9, so it ends up looking like this.
In order to get W by itself, you need to multiply out the denominator.
That means take the denominator and multiply both sides by it.
The -9's cancel out and you are left with W = (11 x -9) which is -99.
W = -99
