That's what I'd guessed, about the meaning.
You just have to be careful about what you move to the other side of the equal sign. For example,
x - (1 - 5) = 3
This would be wrong: x = 3 + 1 + 5 = 9
That first minus sign applies to the entire quantity inside the parentheses. It's actually a -1 and needs to be multiplied with each term in the parentheses.
So it's x -1 + 5 = 3
and then x = 3 + 1 - 5 = -1