All categories

3 years ago

The 4th term of an arithmetic sequence is 12 and the 8th term is 36. Find the 17th term of the sequence.

Mathematics

1 answer:

Blizzard [7]3 years ago

6 0

Answer: 90

Step-by-step explanation:

The formula for calculating the nth term of a sequence is given as :

$t_{n}$ = a + ( n - d )

Where a is the first term

d is the common difference and

n is the number of terms

This means that the 4th term of an arithmetic sequence will have the formula :

$t_{4}$ = a + 3d

And the 4th term has been given to be , 12 ,substituting into the formula we have

12 = a + 3d .............................. equation 1

Also substituting for the 8th term , we have

36 = a + 7d .............................. equation 2

Combining the two equations , we have

a + 3d = 12 ................... equation 1

a + 7d = 36 ------------ equation 2

Solving the system of linear equation by substitution method , make a the subject of formula from equation 1 , that is

a = 12 - 3d ................... equation 3

substitute a = 12 - 3d into equation 2 , equation 2 then becomes

12 - 3d + 7d = 36

12 + 4d = 36

subtract 12 from both sides

4d = 36 - 12

4d = 24

divide through by 4

d = 6

substitute d = 6 into equation 3 to find the value of a, we have

a = 12 - 3d

a = 12 - 3 ( 6)

a = 12 - 18

a = -6

Therefore , the 17th term of the sequence will be :

$t_{17}$ = a + 16d

$t_{17}$ = -6 + 16 (6)

$t_{17}$ = -6 + 96

$t_{17}$ = 90

Therefore : the 17th term of the sequence is 90

You might be interested in

Find the nearest place value. Use #13 to do #14

kondaur [170]

When rounding here are the rules
If the next number to the right is 1-4, you will round down or keep the # the same.
If the next number to the right is 5-9, you will round up to the next number.

So with your # 281,421,906
a. hundred million. This is the first 2...the number to the right of it is 8, so we will round the 2 up. And the answer is 300,000,000
b. ten million. This is the 8...the number to the right of it is 1, so we will round it down and 8 will remain an 8. And the answer is 280,000,000
c. million. This is the first 1 (281)...the number to the right is 4, so we will round down and 1 will remain a 1. And the answer is 281,000,000
d. hundred thousand. This is the 4...the number to the right of it is 2, so we will round down and the 4 will remain a 4. And the answer is 281,400,000
e. thousand. This is the second 1 (281,421)...the number to the right is the 9, so we will round up and the 1 will become a 2. And the answer is 281,422,000

Now for #14, think about the rules.
1. If you round it to the nearest one, you get 7.
2. If you round it to the nearest tenth, you get 7.0.
3. If you round it o the nearest hundredth, you get 7.00
4. It is the least number that fits the clues.

Ok basically it is saying, it rounds up to 7. So what would be the number that would round UP to 7? That would be 6. I'm rounding UP because it says it is the LEAST number that fits the clues.

3 0

3 years ago

Solve for x. Assume that lines which appear to be tangent are tangent.

stiv31 [10]

Answer:

x = 1

Step-by-step explanation:

In order to solve the given problem, we should have the knowledge of the following property.

Measure of the tangents drawn from external points to a circle are equal.

46x - 1 = 45x

46 x - 45x = 1

x = 1

4 0

2 years ago

Find the distance between the following points: (0,0,0) and (-2,6,3)

marusya05 [52]

9514 1404 393

Answer:

3. 7

Step-by-step explanation:

The distance formula applies in 3 dimensions as well as 2.

d = √((x2 -x1)² +(y2 -y1)² +(z2 -z1)²)

d = √((-2)² +6² +3²) = √(4 +36 +9) = √49

d = 7

The distance between the two points is 7 units.

6 0

2 years ago

What is the domain of g(x) = sqrt x +1

Shkiper50 [21]

There can be no negative in a sqrt
so x+1 must be equal or greater then 0
x+1 $\geq$ 0
x $\geq$ -1
so all answers must be greater then or equal to -1
-1,0,1,2,3,4,5,6,7,8
(-1,infinity) is the domain

7 0

3 years ago

A marketing firm is considering making up to three new hires. Given its specific needs, the management feels that there is a 50%

IRISSAK [1]

Answer:

a) 0.9

b) Mean = 1.58

Standard Deviation = 0.89

Step-by-step explanation:

We are given the following in the question:

A marketing firm is considering making up to three new hires.

Let X be the variable describing the number of hiring in the company.

Thus, x can take values 0,1 ,2 and 3.

$P(x\geq 2) = 50\%= 0.5\\P(x = 0) = 10\% = 0.1\\P(x = 3) = 18\% = 0.18$

a) P(firm will make at least one hire)

$P(x\geq 2) = P(x=2) + P(x=3)\\0.5 = P(x=2) + 0.18\\ P(x=2) = 0.32$

Also,

$P(x= 0) +P(x= 1) + P(x= 2) + P(x= 3) = 1\\ 0.1 + P(x= 1) + 0.32 + 0.18 = 1\\ P(x= 1) = 1- (0.1+0.32+0.18) = 0.4$

$\text{P(firm will make at least one hire)}\\= P(x\geq 1)\\=P(x=1) + P(x=2) + P(x=3)\\ = 0.4 + 0.32 + 0.18 = 0.9$

b) expected value and the standard deviation of the number of hires.

$E(X) = \displaystyle\sum x_iP(x_i)\\=0(0.1) + 1(0.4) + 2(0.32)+3(0.18) = 1.58$

$E(x^2) = \displaystyle\sum x_i^2P(x_i)\\=0(0.1) + 1(0.4) + 4(0.32) +9(0.18) = 3.3\\V(x) = E(x^2)-[E(x)]^2 = 3.3-(1.58)^2 = 0.80\\\text{Standard Deviation} = \sqrt{V(x)} = \sqrt{0.8036} = 0.89$

7 0

3 years ago