If we were to draw a best fit line, the y-interest would be near 15, and the slope would be negative.
In the options given, the slope is either -3 or -13. If we imagine a line through the plotted points, the rise would be about 15 while the run would be about 5. This means the slope is about -3.
The best answer is y = -3x + 15
Part A
Answer: The common ratio is -2
-----------------------------------
Explanation:
To get the common ratio r, we divide any term by the previous one
One example:
r = common ratio
r = (second term)/(first term)
r = (-2)/(1)
r = -2
Another example:
r = common ratio
r = (third term)/(second term)
r = (4)/(-2)
r = -2
and we get the same common ratio every time
Side Note: each term is multiplied by -2 to get the next term
============================================================
Part B
Answer:
The rule for the sequence is
a(n) = (-2)^(n-1)
where n starts at n = 1
-----------------------------------
Explanation:
Recall that any geometric sequence has the nth term
a(n) = a*(r)^(n-1)
where the 'a' on the right side is the first term and r is the common ratio
The first term given to use is a = 1 and the common ratio found in part A above was r = -2
So,
a(n) = a*(r)^(n-1)
a(n) = 1*(-2)^(n-1)
a(n) = (-2)^(n-1)
============================================================
Part C
Answer: The next three terms are 16, -32, 64
-----------------------------------
Explanation:
We can simply multiply each previous term by -2 to get the next term. Do this three times to generate the next three terms
-8*(-2) = 16
16*(-2) = -32
-32*(-2) = 64
showing that the next three terms are 16, -32, and 64
An alternative is to use the formula found in part B
Plug in n = 5 to find the fifth term
a(n) = (-2)^(n-1)
a(5) = (-2)^(5-1)
a(5) = (-2)^(4)
a(5) = 16 .... which matches with what we got earlier
Then plug in n = 6
a(n) = (-2)^(n-1)
a(6) = (-2)^(6-1)
a(6) = (-2)^(5)
a(6) = -32 .... which matches with what we got earlier
Then plug in n = 7
a(n) = (-2)^(n-1)
a(7) = (-2)^(7-1)
a(7) = (-2)^(6)
a(7) = 64 .... which matches with what we got earlier
while the second method takes a bit more work, its handy for when you want to find terms beyond the given sequence (eg: the 28th term)
Answer:
x = 5/7
Step-by-step explanation:
4 (0.25 - 2) = x - 0.75 (16 - 8x)
1 - 8 = x - 12 + 6x
1 - 8 + 12 = x + 6x
5 = 7x
5/7 = x
Answer:
24
Step-by-step explanation:
Factorial is applicable only for natural numbers and 0.
0! =1 trivially.
FOr other numbers, factorial is defined as 1x2x...n
For example 1! = 1
2! = 1x2 = 2
and so on.
i.e. n! = product of all natural numbers from 1 to n
= 1x2x....n
Using the above
we have n =4
Natural numbers from 1 to 4 are 1,2,3,4
Find the product of these 4 natural numbers to get 4!
4! = 1x2x3x4 = 24
