$${\mathtt{30}} = {\mathtt{29}}{\mathtt{\,-\,}}{\mathtt{7}}{\mathtt{\,\times\,}}\left({\mathtt{\,-\,}}{\mathtt{2}}{\mathtt{\,-\,}}{\mathtt{2}}{W}\right)$$
Multiply the -7*(-2 - 2W) first, so you get
30 = 29 +14 +14W (remembering that two minuses make a plus)
Simplify:
30 = 43 + 14W
Subtract 43 from both sides:
-13 = 14W
Divide both sides by 14:
W = -13/14
