Question

The first term of an arithmetic sequence is -3 and the fifteenth term is 53. What is the common difference of the sequence?

Answer 1

C: 4 is the right answer

Step-by-step explanation:

Given

a1 = -3

a15 = 53

We know that explicit formula for the arithmetic sequence is:

$a_n=a_1+(n-1)d$

For the 15th, term it will be

$a_{15}=-3+(15-1)d\\53=-3+14d$

Adding 3 on both sides

$53+3 = -3+3 + 14d\\56 = 14d$

Dividing both sides by 14

$\frac{56}{14}=\frac{14d}{14}\\d=4$

Hence,

C: 4 is the right answer

Keywords: Arithmetic sequence, Common Difference

Learn more about arithmetic sequence at:

• brainly.com/question/12896802
• brainly.com/question/12973601

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