Prove the sum of two rational numbers is rational where a,b,c and,d are integers and b and d cannot be zero

Javier works each weekend at an animal shelter. He earns $8 an hour. He is saving his earnings to go on a ski trip that costs $1

Harman [31]

Answer:

Step-by-step explanation:

She earns $8/hour

And she works weekend only

He is saving his earning to go for ski and it cost $190

For him to save $190, let know the hours he is going to work

He earns $8/hour and need $190,

Then he is going to work for

190/8=23.75hours

At least, he needs to work for 24hours and since the 24hours is in a day then, Becca his wrong, he doesn't need extra to work extra 6hours.

We are not told if he need to buy something or do something else we are only told he needs $190 for the trip

4 0

3 years ago

A freshly inoculated bacterial culture of Streptococcus contains 100 cells. When the culture is checked 60 minutes later, it is

Luba_88 [7]

Answer:

$P(t) = 100e^{0.0251t}$

The doubling time is of 27.65 minutes.

Step-by-step explanation:

Exponential equation of growth:

The exponential equation for population growth is given by:

$P(t) = P(0)e^{kt}$

In which P(0) is the initial value and k is the growth rate.

A freshly inoculated bacterial culture of Streptococcus contains 100 cells.

This means that $P(0) = 100$ . So

$P(t) = 100e^{kt}$

When the culture is checked 60 minutes later, it is determined that there are 450 cells present.

This means that $P(60) = 450$ , and we use this to find k. So

$450 = 100e^{60k}$

$e^{60k} = 4.5$

$\ln{e^{60k}} = \ln{4.5}$

$60k = \ln{4.5}$

$k = \frac{\ln{4.5}}{60}$

$k = 0.0251$

So

$P(t) = 100e^{0.0251t}$

Doubling time:

This is t for which P(t) = 2P(0) = 200. So

$200 = 100e^{0.0251t}$

$e^{0.0251t} = 2$

$\ln{e^{0.0251t}} = \ln{2}$

$0.0251t = \ln{2}$

$t = \frac{\ln{2}}{0.0251}$

$t = 27.65$

The doubling time is of 27.65 minutes.

7 0

3 years ago

12-n/7=-1 what y’all think the answer is

mestny [16]

Answer:

19

Step-by-step explanation:

12-n/7 = -1

Cross multiply

We have 12-n = -7

Collect like terms

12 + 7 = n

Therefore n = 19

8 0

3 years ago

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In a week karry ran 9.3 miles and Tricia ran 4.4 miles.Use mental math to find how much farther Karry ran than Tricia.Explain ho

sineoko [7]

Karry ran 4.9 miles more than Tricia. I determined the difference but subtracting the miles to see how many more karry ran.<span />

6 0

3 years ago

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Which expression is equivalent to .02m(n - 5) - .02(m + 10)? A) .02mn - .12m - 0.2 B) .02mn + .12m - 0.2 C) .02mn - .12m + 0.2 D

VikaD [51]

The correct answer is A)<span>.02m(n - 5) - .02(m + 10)</span>

7 0

3 years ago

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