If there's a negative in front of a difference, the expression can be rewritten by remove the parentheses, change signs, and rearrange the terms as follows. -(9−x)=-9+x=x−9 \text{-}(9-x)=\text{-} 9+x=x-9 -(9−x)=-9+x=x−9 All this can be done in a single step.