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3 years ago

4x - 7y = 3 x - 7y = 15

1 answer:

5 0

$\left \{ {{4x-7y=3} \atop {x-7y=15}} \right. \\\\
 \left \{ {{4x-7y=3} \atop {x=15+7y}} \right. \\\\ substitution\ method\\\\
4*(15+7y)-7y=3\\\\
60+28y-7y=3\\\\
60+21y=3\ \ \ \ | subtract\ \\\\
21y=-57\\\\
y=-\frac{57}{21}=-\frac{19}{7}\\\\
x=15+7*(-\frac{19}{7})=15-19=-4\\\\\ Solution :\ \left \{ {{y=-\frac{19}{7}} \atop {x=-4}} \right.$

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snow_lady [41]

Answer:

A. It provides carbon monoxide to help plants grow.

Step-by-step explanation:

The only incorrect option is that carbon monoxide is required by plant, but the correct statement would be carbon dioxide is required my plants, for its growth, which helps to perform the process of photosynthesis.

The rest of the statements are correct.

As, the atmosphere acts as a blanket, which protects the earth from the harmful rays of the sun.

And, atmosphere constitute of various gases, which enables the living organisms to breath.

And, the atmosphere protects from any meteors entering from space.

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3 years ago

*WILL GIVE BRAINLIEST* the following function represents the production cost f(x), in dollars, for x number of units produced by

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Answer:

Step-by-step explanation:

By analyzing the functions f(x) and g(x), we can see that they are both quadratic relations.

To find the minimum value, we want to find the y-coordinate of the vertex.

In f(x), by using the formula (-b/2a), we get the x-coordinate of the vertex, 70. When we substitute 70 into the function, we get 55 as our minimum.

In h(x), we can see that the lowest y-coordinate in the given points is 899.52. So (1, 899.50) is our vertex.

This means that in f(x), the minimum production cost is $70. In contrast, in h(x), the minimum production cost is $899.50. Therefore f(x) has a lower minimum, with its minimum value at (70, 55), our vertex.

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2 years ago

This cubiod is made from 6 small cubes write how many small cubes there are in this cubiod

BARSIC [14]

Answer:

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Step-by-step explanation:

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2 years ago

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3 years ago

This graph shows the temperature of a room over time.

Arturiano [62]

Answer:

<u>The correct answer is C. Aaron turns on the heat and the temperature of a conference room steadily increases. After the room becomes a comfortable temperature, Aaron turns off the heat and the temperature in the room stays the same for a while. Aaron’s coworker says it is too hot in the room, so Aaron turns on the air conditioner. The temperature in the room steadily decreases. Aaron gets cold again and turns the heat back on so that the temperature of the room steadily increases. Again, when the room becomes comfortable, Aaron turns off the heat and the temperature of the room stays the same.</u>

Step-by-step explanation:

1. Let's see what happens in the conference room the first 20 minutes, according to the graph:

The temperature increase from 65 °F to 75 °F. This fact discards immediately answer B, that mentions that "the temperature of the room decreases steadily to a comfortable temperature".

2. Let's see what happens in the conference room the next 20 minutes (between minutes 20 and 40), according to the graph:

The temperature remains at 75 °F, at a comfortable temperature, during these 20 minutes. This fact discards answer D because it mentions that the "room becomes too hot", which is not true because the additional 10 °F of increase is most likely, not "too much" and it also considers 65 °F as "too cold".

3. Let's see what happens in the conference room between minutes 40 and 50, according to the graph:

In ten minutes, the temperature decreases from 75 °F to 65 °F, which was the original temperature of the room. No big difference between answers A and C, the only that are still valid.

4. Let's see what happens in the conference room between minutes 50 and 80, according to the graph:

In these 30 minutes, the temperature of the conference room again increases between minutes 50 and 70 from 65 °F to 75 °F. This last fact discards the answer A, that mentions that " finally, Aaron turns the heat back on and the temperature of the room increases steadily for the rest of the conference". What actually happened is that the temperature becomes comfortable again and stays the same the rest of the conference.

<u>This is a detailed explanation why we discard answers A, C and D and we select answer C as the right one.</u>

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2 years ago