Question

Help with this question please!

Answer 1

48 and 39, nth term = 93 - 9n, 21 st term = - 96

there is a difference (d) of - 9 between the terms

d = 75 - 84 = 66 - 75 = 57 - 66 = - 9

rule is : subtract 9 from each term to obtain next term in sequence

This is an arithmetic sequence and the n th term is found using

`a_(n)` =
`a_(1)` + (n - 1)d

where
`a_(1)` is the first term and n = 21

thus
`a_(21)` = 84 + (20 × - 9) = 84 - 180 = - 96

Answer 2

84,75,66,57,48,39 the rule is 369