

\
The expression is 
=
(Remove parenthesis)
=
(Commutative property: a + b = b + a) \ \
=
(Assosiative property: a + (b + c) = (a + b) + c)
=
(Distributive property:
)
=
(Subtract:
)
=
(Subtract:
)
The simplified expression is
.