Question

What is the 23rd term in the arithmetic sequence 11,14,17,20?

Answer 1

To find the next term in an arithmetic sequence, your best bet would be to use the formula N(x)= N(1) + (x-1)*d, where x stands for the term you want to find, N(1) stands for the first number in the sequence, and d stands for the common difference between the numbers.

First, lets see what we can plug in. We know the first term in the sequence (N(1)) is 11, we know that we want to find the 23rd number in the sequence (x), and by subtracting the 2nd term by the 1st term (14-11), the common difference (d) is 3. When we plug that all into our equation, it should end up looking something like this: N(23)= 11 + (23-1)*3.

Next, we can break down the equation to solve it step by step using PEMDAS. Parenthesis go first, so N(23)= 11 + (23-1)*3 becomes N(23)= 11 + (22)*3. We don't have any exponents, so we can skip the E. Next, we do multiplication and division from left to right, so N(23)= 11 + (22)*3 becomes N(23)= 11 + 66. Finally, we do addition and subtraction from left to right, getting us from N(23)= 11 + 66 to N(23)= 77, which means that the 23rd number in the sequence is 77!