Find the Common Difference for the Arithmetic Sequence $2 , - 1 , - 4 , - 7 , \ldots$

Q65: Use mathematical induction to prove that the

Q66: Find the first six terms of

Q67: Solve the problem.<br>-The beginning population of a

Q68: It can be shown that

Q69: Solve the problem.<br>-Find the sum of the

Q71: Solve the problem.<br>-A town has a population

Q72: Write the binomial expansion of the

Q73: Find the first term and the

Q74: Write the indicated term of the

Q75: Find the nth term of the