Can someone please help me? I have this part figured out.$15660x2/3x1/2=5220.($15660-5220)x2/3=6960. ...

It appears that you are confused because the way various
expressions are represented, these can be interpreted in different ways. You can
represent the expression more clearly as:

Instead
of:

I.

15660x2/3x1/2=5220.

15660
x (2/3) x (1/2) = 5220

This can be simplified
as:

==> 15660 x (2x1)/(3x2) =
5220

==> 15660 x (1/3) =
5220

==> 15660/3) =
5220

In this case:

($15660 -
answer) x (2/3) = answer, becomes

($15660 - 5220) x (2/3) =
5220

II.

Similarly Instead
of:

(15660-5220)x2/3=6960.

(15660
- 5220) x (2/3) = 6960

This can be simplified
as:

==> (10440) x (2/3) =
6960

==> (10440 x 2)/3 =
6960

==> 20880/3 =
6960

In this case:

($15660 -
answer) - $600 = answer, becomes,

($15660 - 6960) - $600 =
6960

Please note that this equation is not correct. There
appears to be some error in question posted. The correct value of ($15660 - 6960) -
$600  is 8100

This equation can be balanced with value of
answer as 7530. Then the equation becomes:

($15660 - 7530)
- $600 = 7530