Your answer: 65 * 0.1 = 6.5
For (-7,3) and (5,3) the answer is 12. You add the different points, -7 and 5 because one is negative and one is positive. You do not add 3 and 3 because they are the same.
(3,-6) and (3,-10) = 4 because -6 and -10 are negatives. The answer is always positive.
(8,0) and (8,-8) = 8.
To answer this, you just go around multiplying the terms from the first set by everything in the second set. (For example, multiply 2x^2 by x^2, next by -2x, and finally by 5)
If it is a cylinder then and assuming radius is in cm
V = pi(r)^2(h)
V = 3.14*(3)^2*4.1
V = 115.866 cm^3