Original function is
.
Replace x = 4 in original function.
\
Evaluate powers:
.

(Multiply:
)
Apply commutative property of addition: a + b = b + a.
\
(Add: 128 + 4 = 132)
= 100 (Subtract:
)
Replace x =
2 in original function.

(Evaluate power:
)
(Multiply:
)
(Divide:
)
(Apply additive inverse property:
)
, and
.