1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Lerok [7]
2 years ago
14

the average of the five number was 6.8. If the first four numbers were 4.3, 5.2, 7, and 6.8, What was the fifth number?

Mathematics
1 answer:
Nikolay [14]2 years ago
6 0
Let x be the fifth number
\frac{4.3 + 5.2 + 7 + 6.8 + x}{5} = 6.8
⇔ \frac{23.3 + x}{5} = 6.8
⇔ 23.3 + x = 34
⇔ x = 10.7
You might be interested in
Systems of linear equations ; elimination method<br><br><br> pls help&lt;3
Basile [38]
<h3>Answer:</h3>

System

  • 10s +25t = 11700
  • s -2t = 0

Solution

  • s = 520
  • t = 260
<h3>Explanation:</h3>

Let s and t represent single-entry and three-day tickets, respectively. These variables represent the numbers we're asked to find: "how many of each [ticket type] he sold."

We are given the revenue from each ticket type, and the total revenue, so we can write an equation based on the relation between prices, numbers sold, and revenue:

... 10s +25t = 11700 . . . . . equation for total revenue

We are also given a relation between the two number of tickets sold:

... s = 2t . . . . . . . . . . . . . . . twice as many single tickets were sold as 3-day

We can rearrange this second equation to put it into standard form. That makes it easier to see what to do to eliminate a variable.

... s -2t = 0 . . . . . . . . . . . . subtract 2t to put into standard form

So, our system of equations is ...

  • 10s +25t = 11700
  • s -2t = 0

<em>What </em>elimination<em> is all about</em>

The idea with "elimination" is to find a multiple of one (or both) equations such that the coefficients of one of the variables are opposite. Then, the result of adding those multiples will be to eliminate that variable.

Here, we can multiply the second equation by -10 to make the coefficient of s be -10, the opposite of its value in the first equation. (We could also multiply the first equation by -0.1 to achieve the same result. This would result in a non-integer value for the coefficient of t, but the solution process would still work.)

Alternatively, we can multiply the first equation by 2 and the second equation by 25 to give two equations with 50t and -50t as the t-variable terms. These would cancel when added, so would eliminate the t variable. (It seems like more work to do that, so we'll choose the first option.)

<em>Solution by elimination</em>

... 10s +25t = 11700 . . . . our first equation

... -10s +20t = 0 . . . . . . . second equation of our system, multiplied by -10

... 45t = 11700 . . . . . . . . .the sum of these two equations (s-term eliminated)

... t = 11700/45 = 260 . . . . . divide by the coefficient of t

... s = 2t = 520 . . . . . . . . . . use the relationship with s to find s

_____

<em>Solution using your number sense</em>

As soon as you see there is a relation between single-day tickets and 3-day tickets, you can realize that all you need to do is bundle the tickets according to that relation, then find the number of bundles. Here, 2 single-day tickets and 1 three-day ticket will bundle to give a package worth 2×$10 + $25 = $45. Then the revenue of $11700 will be $11700/$45 = 260 packages of tickets. That amounts to 260 three-day tickets and 520 single-day tickets.

(You may notice that our elimination solution effectively computes this same result, where "t" and the number of "packages" is the same value (since there is 1 "t" in the package).)

6 0
3 years ago
If a laptop originally costs $800, the balance due after the 10% discount and $150 gift card is applied is $.
timama [110]
If a laptop originally costs $800 at purchase, and is then discounted by 10%, the remainder would be $720, given that 10% of $800 is $80. Therefore, once then applying the credit card to reduce it another $150, the final price of the laptop would come out to $570 once the deductions are considered.
4 0
3 years ago
Read 2 more answers
Help me plssssssss this is a math question
Flura [38]
“My neighbor owns his own property” your book said non mathematical, but tell me if it’s supposed to be. I can write you a new one.
8 0
3 years ago
Elisa is making candles she knows each candle needs a wick that is 4 inches long.she wants to make 7 candles how many inches of
dimulka [17.4K]
She will need 28 inches of wick
4 0
3 years ago
Read 2 more answers
The atmosphere flows in large convection currents.
OleMash [197]
B. Warm air rises,and cool air sinks.
7 0
3 years ago
Read 2 more answers
Other questions:
  • sally and martha had the same number postcards. after sally sold 18 of her postcards, martha had 4 times as many postcards as sa
    11·1 answer
  • Approximately 325,563 babies were born in Texas in 1991. What was the average number of births each week?
    10·1 answer
  • How do you solve literal eqations
    14·1 answer
  • Choose the equation that represents the graph below: (1 point) Graph of a line passing through points 0 comma 6 and 9 comma 0 y
    10·1 answer
  • Me ayudan plissssssss
    7·1 answer
  • NEED HELP ASAP WILL GIVE BRAINLIEST
    14·1 answer
  • What is the length of y in this picture? <br> X <br> 45° <br> 5
    8·1 answer
  • There are 15 balls in an urn. 5 red balls, 5 blue balls and 5 white balls. Three balls are taken simultaneously. Let X represent
    7·1 answer
  • 68 divided by 0.4. Show work please.
    5·1 answer
  • ¿Cuánto recorre aproximadamente una rueda que da 60 vueltas si ésta tiene un radio de 0.20 m?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!