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3 years ago

A swimming pool is open for 7 1/2hours during a day. The pool keeps one lifeguard on

Mathematics

2 answers:

denis23 [38]3 years ago

4 0

Answer:

3 shifts a day

Step-by-step explanation:

7 1/2 hours = 7.5 2 1/2 hours = 2.5

7.5 divided by 2.5 = 3

fredd [130]3 years ago

4 0

Answer:

3 shift

Step-by-step explanation:

7 1/2 / 2 1/2

(15/2) / (5/2)

keep, change, flip

(15/2) x (2/5)

30/10 = 3 shifts

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Due to erosion, a beach is

Olenka [21]

Answer:

17 years

Step-by-step explanation:

do 85 divided by 5

5 0

3 years ago

Read 2 more answers

Solve the following recurrence relation: <br> <img src="https://tex.z-dn.net/?f=A_%7Bn%7D%3Da_%7Bn-1%7D%2Bn%3B%20a_%7B1%7D%20%3D

-Dominant- [34]

By iteratively substituting, we have

$a_n = a_{n-1} + n$

$a_{n-1} = a_{n-2} + (n - 1) \implies a_n = a_{n-2} + n + (n - 1)$

$a_{n-2} = a_{n-3} + (n - 2) \implies a_n = a_{n-3} + n + (n - 1) + (n - 2)$

and the pattern continues down to the first term $a_1=0$ ,

$a_n = a_{n - (n - 1)} + n + (n - 1) + (n - 2) + \cdots + (n - (n - 2))$

$\implies a_n = a_1 + \displaystyle \sum_{k=0}^{n-2} (n - k)$

$\implies a_n = \displaystyle n \sum_{k=0}^{n-2} 1 - \sum_{k=0}^{n-2} k$

Recall the formulas

$\displaystyle \sum_{n=1}^N 1 = N$

$\displaystyle \sum_{n=1}^N n = \frac{N(N+1)}2$

It follows that

$a_n = n (n - 2) - \dfrac{(n-2)(n-1)}2$

$\implies a_n = \dfrac12 n^2 + \dfrac12 n - 1$

$\implies \boxed{a_n = \dfrac{(n+2)(n-1)}2}$

4 0

2 years ago

This expression is factored what is it's trinomal form?<br> (5x+2)(x-3)

Mkey [24]

Answer:

5x² - 13x - 6

Step-by-step explanation:

Each term in the second factor is multiplied by each term in the first factor, that is

5x(x - 3) + 2(x - 3) ← distribute both parenthesis

= 5x² - 15x + 2x - 6 ← collect like terms

= 5x² - 13x - 6

8 0

3 years ago

Elm Street is straight. Willard's house is at point H between the school at point S and

Vlad1618 [11]

Answer:

7.5 Miles.

Step-by-step explanation:

3 + 4.5 = 7.5 Miles.

4 0

3 years ago

Natalie has 350 pencils. She is packing them in boxes that each hold 14 pencils. How many boxes will Natalie fill with pencils?

ohaa [14]

Answer:

Step-by-step explanation:

350/14=25

Natalie will fill 25 boxes with pencils.

3 0

3 years ago