So basically an arithmetic sequence has a common difference, a number which is either added or subtracted at a constant rate (only that number). A geometric sequence is the ratio between two numbers, meaning they are either multiplied or divided by the same number. The sequence would be neither if it follows none of these patterns. So by this logic:
14. Arithmetic, 15. Geometric, 16. Neither, 17. Geometric
The answer is 2x+6
Explanation: 2 times 3 is 6 and 2 times x is 2x
Answer:
Although the notation is sloppy, I will assume based on former questions of the same that "∑n=15[5(−2)^n−1]" translates mathematically to . Please correct me, though, if this in incorrect.
Anyway, there is neat formula that will deal with question very quickly. It is the following:
Sn is the sum of the geometric series
a1 is the first term in the series
r is the common ratio
n is the number of terms in the finite geometric series
Let's use this formula to our advantage! However, there are two variables that we do not know: a1 and n. Let's start with a1.The first term in the series is when n=1, so let's determine what that is.
Answer:
r=1
Step-by-step explanation:
-4 r -10r + -5= -19
-4r + (-10r) + -5=-19
-14r+ -5 = -19
-14r + -5 +5= -19+5
-14r= -14
r=1