Which is a counterexample to this conjecture?

the sum of any two consecutive integers is a composite number.

a.
16 + 17 = 33 b.10 + 11 = 21 c.6 + 7 = 13 d.7 + 8 = 15

Factor this polynomial completely x^2-64

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

Amovie streaming service charges it’s customers $15 a month. martina has $98 saved up. will she have any money left over if she pays for the maximum amount of months she can afford? explain.