Good explanation Zac but 2-5=-3  not -7 so it is not going to be quite right.    

Doesn't really matter - your explanation of how to go about finding the answer is very good :)    

2 - (7x + 5) = 13 - 3x.......Expand the brackets

2 - 7x - 5 = 13 -3x..........Group like terms

-7x - 3 = -3x + 13

-16 = 4x........................Divide both sides by 4

x = -4

(Fixed!  )