The terms in the first parentheses are X3 and -1

The terms in the second parentheses are: X7, -2X4, -5X2, and 5

1.  Multiplying the X3 times the X7 gives X10.
2.  Multiplying the X3 times the -2X4 gives -2X7.
3.  Multiplying the X3 times the -5X2 gives -5X5.
4.  Multiplying the X3 times the 5 gives +5X3.
5.  Multiplying the -1 times the X7 gives -X7.
6.  Multiplying the -1 times the -2X4 gives +2X4.
7.  Multiplying the -1 times the -5X2 gives +5X2.
8.  Multiplying the -1 times the +5 gives -5.

A.  The only term in X11 is given by 1 above as X10.
B.  The terms in X7 are given in 2 as -2X7 and in 5 
         above as -1X7 which combine to give -3X7.
C.  The only term in X5 is given by 3 above as -5X5.
D.  The only term in X4 is given by 6 above as +2X4.
E.  The only term in X3 is given by 4 above as +5X3.
F.  The only term in X2 is given by 7 above as +5X2.
G.  The only constant term is given in 8 as -5.

Answer: X10-3X7-5X5+2X4+5X3+5X2-5

Edwin