Answer:
a) Arithmetic
b) 22.5
c) 4.5
d) a_n = 4.5 + 4.5(n - 1)
e) a_15 = 67.5
Step-by-step explanation:
a) Subtract one term by the term right before it, and the difference will be the common difference.
9 - 4.5 = 4.5
13.5 - 9 = 4.5
18 - 13.5 = 4.5
Therefore, the common difference is 4.5.
b) Since the common difference is 4.5, add 4.5 to the 18 (which was the last value given). The result is 22.5.
c) We have already figured out that the common difference is 4.5.
d) The explicit formula would be a_n = a1 + d(n - 1). The first term is 4.5 and d is also 4.5, so the explicit formula is a_n = 4.5 + 4.5(n-1).
e) Plug 15 into our explicit formula for n. a_15 = 4.5 + 4.5(14). The result is 67.5.
Answer:

Step-by-step explanation:
We start off with 3.2n + 13.3 = 26.1.
We need to get n by itself.
Subtract 13.3 from both sides.


We end up with: 
Divide 3.2 on both sides to get n by itself.

Answer:
y=2x+5
Step-by-step explanation:
To find a linear equation you must find the slope and y intercept to create an equation in y=mx+b form (slope-intercept form)
So slope is = y2-y1 / x2-x1 [2 and 1 are subscripts] so 11-7/3-1 so m=4/2 = 2
Slope = 2, now find b
So using y = mx + b, substitute what you know so 7 = 2(1) + b so b=7-2 = 5
Put it all together y = 2x + 5
Answer:
17
Step-by-step explanation:
Answer:
The moon has moved past the full moon and is moving toward the third quarter.
Step-by-step explanation: