Answer
Fill the blank with
$x+658.6$
Work Step by Step
"...exceeded x by $\$ 658.6$ (billion) "
means, assuming that we are expressing values in billions of dolalrs,
"...is 658.6 more than x",
which we can express as
"... equals 658.6 added to x"
or, symbollically,
$x+658.6$.
Fill the blank with
$x+658.6$
