Answer:
f(n) = 6n + 12
Step-by-step explanation:
There is a common difference in consecutive number of seats, that is
42 - 36 = 36 - 30 = 30 - 24 = 24 - 18 = 6
This indicates the sequence is arithmetic with nth term
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = 18 and d = 6 , then
f(n) = 18 + 6(n - 1) = 18 + 6n - 6 = 6n + 12
Answer:
28
Step-by-step explanation:
40% 6th graders of 70 total = 28 6th graders
40% 6th graders + 20% 7th graders = 60%
100% - 60% = 40% 8th graders
40% are 8th graders therefore the answer is 28
Answer:
54
Step-by-step explanation:
since n = 3
= -2n ( 5n+n-8-3n)
= -2 (3) ( 5+(3)-8-3(3) )
= -6 (5+3-8-9)
= -6 (5-5-9)
= -6 (-9)
= 54.