What would be the answer for number 3?

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

Find the common ratio of the sequence. -4, 8, -16, 32, a: -12b: -2c: 12d: -1/-2