from 19 to 26 there is a diff. of 7. from 26 to 36 there's a diff of 10. the difference of the differences are increased by 3, and if you try adding 13 onto 36 it will be 49, which have a diff of 16(13+3) with 65, which makes the last number 65+19=84 the two answers for the two blanks are 49 and 84.
