In 1 1/2 hours john can walk 4 1/2 miles find his average speed in miles per hour.

PLEASE HELP ILL MARK BRAINLIEST !!!

Alexus [3.1K]

Answer:

a) the common difference is 20

b) $x_8=115 , x_{12}=195$

c) the common difference is -13

d) $a_{12}=52, a_{15}=13$

Step-by-step explanation:

a) what is the common difference of the sequence xn

Looking at the table, we get x_3=16, x_4=36 and x_5= 56

Deterring the common difference by subtracting x_4 from x_3 we get

36-16 =20

So, the common difference is 20

b) what is x_8? what is x_12

The formula used is: $x_n=x_1+(n-1)d$

We know common difference d= 20, we need to find $x_1$

Using $x_3=16$ we can find $x_1$

$x_n=x_1+(n-1)d\\x_3=x_1+(3-1)d\\15=x_1+2(20)\\15=x_1+40\\x_1=15-40\\x_1=-25$

So, We have $x_1 = -25$

Now finding $x_8$

$x_n=x_1+(n-1)d\\x_8=x_1+(8-1)d\\x_8=-25+7(20)\\x_8=-25+140\\x_8=115$

So, $\mathbf{x_8=115}$

Now finding $x_{12}$

$x_n=x_1+(n-1)d\\x_{12}=x_1+(12-1)d\\x_{12}=-25+11(20)\\x_{12}=-25+220\\x_{12}=195$

So, $\mathbf{x_{12}=195}$

c) what is the common difference of the sequence $a_m$

Looking at the table, we get a_7=104, a_8=91 and a_9= 78

Deterring the common difference by subtracting a_7 from a_8 we get

91-104 =-13

So, the common difference is -13

d) what is a_12? what is a_15?

The formula used is: $a_n=a_1+(n-1)d$

We know common difference d= -13, we need to find $a_1$

Using $a_7=104$ we can find $x_1$

$a_n=a_1+(n-1)d\\a_7=a_1+(7-1)d\\104=a_1+7(-13)\\104=a_1-91\\a_1=104+91\\a_1=195$

So, We have $a_1 = 195$

Now finding $a_{12}$ , put n=12

$a_n=a_1+(n-1)d\\a_{12}=a_1+(12-1)d\\a_{12}=195+11(-13)\\a_{12}=195-143\\a_{12}=52$

So, $\mathbf{a_{12}=52}$

Now finding $a_{15}$ , put n=15

$a_n=a_1+(n-1)d\\a_{15}=a_1+(15-1)d\\a_{15}=195+14(-13)\\a_{15}=195-182\\a_{15}=13$

So, $\mathbf{a_{15}=13}$

5 0

3 years ago

The circumference of a circular hot tub at a hotel is 56.5 yards. What is the diameter of the hot tub?

Scorpion4ik [409]

$c = 2\pi \times r \\ 56.5 \div 2 = \pi \times r \\ 28.25 \div \pi = r \\ 9 = r \: then \: \times 2 = d \: \\ diameter \: is \: 18$

7 0

3 years ago

Northern Bank has two types of account. Both accounts pay compound interest. Cash savings account Interest 2.5% per annum Shares

musickatia [10]

Answer: Ben will have the most interest.

Step-by-step explanation:

Ali after 3 years.

To use compound interest, the formula is:

= Investment * ( 1 + rate) ^ no. of periods

= 2,000 * ( 1 + 2.5%)³

= £‭2,153.78

Interest = Amount after 3 years - investment

= 2,153.78 - 2,000

= £153.78

Ben after 3 years.

= 1,600 * (1 + 3.5%)³

= £1,773.95

Interest = 1,773.93 - 1,600

= £173.93

4 0

3 years ago

Jackson has three cartons of gumballs. There are 100 boxes in each carton. There are 100 gumballs in each box

lilavasa [31]

Answer:

3. 10000

Step-by-step explanation:

Given the following :

Number of gumball cartons = 3

Number of boxes per carton = 100

Number of gumballs per box = 100

The number of gumballs can be expressed in the form : (a. 10) ; where ; a = prime number ; b = whole number

Values of a and b?

Total number of gumballs :

Number of carton × number of boxes per carton × number of gumballs per box

3 × 100 × 100

Hence, writing the expression in the form: a. 10

a. 10 = 3 × 10000

4 0

3 years ago

Tell whether the given value is a solution of the inequality

kipiarov [429]

Answer:

Yes it is, because...

Step-by-step explanation:

This is an inequality, so you can treat it as an algebraic expression.

The first step is to multiple both sides by 2, to get rid of the 2 on the left side.
Your equation will now look like this:
y >= 2y - 22

The next step is to get all the y variables to one side, now that its a lot more simplified. Subtract 2y from both sides to get:
-y >= -22

Finally, cancel out the negative on both sides of the equation to get the y as a positive y, all by itself. This will get you:
y <= 22

REMINDER: when you divide by a negative number, such as in this case dividing by -1 on both sides, the inequality sign will flip!

y = 18 works because it is less than 22. (:

8 0

2 years ago

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