Would it help if you wrote it as
[tex]\dfrac{x}{-11} = \dfrac{-3}{1}[/tex] ?
Then you can cross multiply if you know how to do that.
1*x = (-11)(-3)
x = 33 but what happened to the 2 minus signs?
Remember that a ( - ) times a ( - ) = a plus. The two minus signs become a plus.
