Question

3. 10th term of an arithmetic sequence is 15 and its 30th term is 55. a) What is the common difference of this sequence ?b) What is the 40th term of this sequence?​

Answer 1

Step-by-step explanation:

a+9d=15

a+29d=55

By solving we get d=2

&by substituting d=2 in a+9d=15

we get a= -3

40 th term is obtained by substituting a&d in a+39d= -3+78=75