What is the scale factor from Figure A to Figure B?

Which is an equation for the nth terms of the sequence 12,15,18,21

Plzzz plzz maths ! quadratic sequences =an^2+bn 1) 1,6,15,28,45 2)5,18,39,68,105 3) 1,8,21,40,65 4) 7,24,51,88,135 5) -1,2,9,20,35

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.