The formula for an arithmetic sequence is shown below, where n = 1, 2, 3… F(n)=3n-9 What are the sixth, seventh, and eighth terms in the sequence? A. 6, 9, 12 B. 9, 10, 11 C. 15, 18, 21 D. 9, 12, 15

D: 9, 12, 15

Step-by-step explanation:

Okay, this one is a very simple and a not so hard question. I understand that teachers prefer kids to not lay out all the terms, but in this case, it won´t be horrible in doing so!

Were going to plug 6 into n, and that will make the formula look like,

F(6)=3(6)-9

18-9=9 so the 6th term is 9

Plug in 7=

F(7)=3(7)-9

21-9=12

The 7th term is 12

Plug in 8=

F(8)=3(8)-9

24-9=15  8th term is 15

That means terms 6, 7, and 8 are: 9, 12, 15

4 + 5 7/9= 9 7/9

step-by-step explanation:

your answer is 228

step-by-step explanation:

add the top and bottom bases together, then divide them by 2, then multiply by the height.