D, a theme is usually a message or life lesson to the characters or reader :)
Midpoint = (8-5),(-3-9) / 2
= (3,-12)/2
= (3/2,-6)
You break up the 207 into smaller numbers you can work with. 9 can go into 20 a maximum of 2 times, so you subtract 2*9 or 18 from 20. Then, you bring down the 7. 9 goes into 27 exactly 3 times, so you have 9*23=207.