Question

The first term of an arithmetic sequence is -3 and the fifteenth term is 53. What is the common difference of the sequence? 14/13 25/7 4

Answer 1

Answer:

The common difference of the arithmetic sequence is:

                                       4

Step-by-step explanation:

We kn ow that if the first term of an arithmetic sequence is a and d is the common difference of the sequence then the nth term of the sequence is given by the formula:

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

Here we are given:

$a=-3$

and

$a_15=53\\\\i.e.\\\\a+(15-1)d=53\\\\i.e.\\\\a+14d=53$

Now using the value of a we have:

$-3+14d=53\\\\i.e.\\\\14d=56\\\\i.e.\\\\d=4$

Answer 2

$a_1=-3 \\ a_{15}=53 \\ \\ d= \frac{53-(-3)}{15-1}= \frac{56}{14}=4$

The answer is d=4