Identify the 42nd term of an arithmetic sequence where a1 = -12 and a27 = 66

Question

campbell_st · Answer

well to complete this question you need to find the common difference before finding the 42nd term 

the formula for a term in an arithmetic sequence is 

$$T_{n} = a + (n - 1)d $$

a = 1st term, n = number of terms and d is the common difference 

so using the known information you can say 

$$66 = -12 + (27 -1) d$$

you need to solve for d..

$$66 = -12 + 26d$$

when you have d, using the formula above with n = 42 to find the 42nd term 

hope it helps