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Sholpan [36]
3 years ago
11

rob can tar a roof in nine hours. one day his friend kayla helped him and it only took 4.74 hrs. how long will it take kayla to

do it alone?
Mathematics
1 answer:
jekas [21]3 years ago
7 0
<span>When 2 people work the formula is: Person1 * Person2 / (Person1 + Person2)
</span> 
<span>rob becomes Person1 and Kayla becomes Person 2
 9 * K / (9 + K) = 4.74 Hours
 9*K = 4.74*9 + K*4.74
 9*K = 42.66 + K*4.74 4.26 *K = 42.66 K = 10.014084507 hours (Kayla)
  TESTING the answer (9 * 10.014084507) / (9 + 10.014084507) = 4.74 90.126760563 / (19.014084507) = 4.74
 4.74 = 4.74
</span>
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V<img src="https://tex.z-dn.net/?f=%5Cfrac%7B3%7D%7B4%7D%20%2A%202%5Cfrac%7B1%7D%7B3%7D" id="TexFormula1" title="\frac{3}{4} * 2
myrzilka [38]

Answer:

1\frac{3}{4}

Step-by-step explanation:

In order to find the answer, you first need to convert the mixed number (2 1/3) into a improper fraction and then multiply.

\frac{3}{4} \times2\frac{1}{3}

2\frac{1}{3} =3\times2=6+1=7=\frac{7}{3}

\frac{3}{4} \times\frac{7}{3}

3\times7=21

4\times3=12

=\frac{21}{12} =\frac{7}{4} =1\frac{3}{4}

=1\frac{3}{4}

Hope this helps.

7 0
3 years ago
Five times a number subtracted from 18 is triple the number find the number
Bess [88]
The number is 18

hope this helps
4 0
3 years ago
Which is the completely factored form of 4x2 28x 49? (x 7)(4x 7) 4(x 7)(x 7) (2x 7)(2x 7) 2(x 7)(x 7)
natima [27]

The completely factored form of 4x^2 + 28x + 49 is given by: Option C: (2x+7)(2x+7)

<h3>How to find the factors of a quadratic expression?</h3>

If the given quadratic expression is of the form ax^2 + bx + c, then its factored form is obtained by two numbers alpha( α ) and beta( β) such that:

b = \alpha + \beta \\ ac =\alpha \times \beta

Then writing b in terms of alpha and beta would help us getting common factors out.

Sometimes, it is not possible to find factors easily, so using the quadratic equation formula can help out without any  trial and error.

For this case, the given quadratic expression is:

4x^2 + 28x + 49

So we've to find two numbers such that:

Their sum = b =  28

Their product = ac = 4\times 49 = 196

We can see that 196 is square of 14, and that 14 added twice forms 28, thus:

14 + 14 = 28

14×14 = 196

Writing b = 28 as sum of 14 twice, we get:

4x^2 + 28x + 49 = 4x^2 + 14x + 14x +49 \\4x^2 + 28x + 49 =  2x(2x+7) + 7(2x + 7)\\4x^2 + 28x + 49  = (2x+7)(2x+7)

Thus, the completely factored form of 4x^2 + 28x + 49 is given by: Option C: (2x+7)(2x+7)

Learn more about factorization of quadratic expression here:

brainly.com/question/26675692

8 0
2 years ago
The gas tank on your lawn mower holds 1/8 gallon of fuel. You can mow 2 1/4 lawns with one tank of fuel. At this rate, how many
blagie [28]
At 1/8 of a gallon you can mow 2 1/4 so for 1 gallon just multiply 2 1/4 by 8
16+2 is 18
5 0
3 years ago
A 56-inch Woman cast a shadow that is 16 inches long. How tall is her child if his shadow is 14 inches long?
nikitadnepr [17]

Answer:49

Step by step is 56÷16=3.5

14x3.5=49

6 0
3 years ago
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