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KengaRu [80]
3 years ago
11

Solve the system of equations given below. -5x = y – 5 -2y = -x-21

Mathematics
1 answer:
irakobra [83]3 years ago
3 0

Answer:

<h2>x = -1, y = 10 → (-1, 10)</h2>

Step-by-step explanation:

\left\{\begin{array}{ccc}-5x=y-5&\text{subtract y from both sides}\\-2y=-x-21&\text{add x to both sides}\end{array}\right\\\left\{\begin{array}{ccc}-5x-y=-5&\text{multiply both sides by (-2)}\\x-2y=-21\end{array}\right\\\underline{+\left\{\begin{array}{ccc}10x+2y=10\\x-2y=-21\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad11x=-11\qquad\text{divide both sides by 11}\\.\qquad x=-1\\\\\text{put the value of x to the first equation:}\\\\10(-1)+2y=10\\-10+2y=10\qquad\text{add 10 to both sides}\\2y=20\qquad\text{divide both sides by 2}\\y=10

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PLEASE HELPPP!!!! Will give brainiest!!!!
Lady_Fox [76]

Answer:

  • 0.008 °C

Explanation:

<u>1) Write the changes in the temperature of the city over the 4 days in an easy way to read.</u>

<u />

  • 1.34 °C
  • - 5 / 7 °C
  • - 0.75 °C
  • 4/9 ° C

<u />

<u>2) Write the expression to show the average daily change in temperature.</u>

The average of a set of data is calculated with the expression:

  • Average = (sum of the data) / amount of data

Hence, you need to add the four change of temperature data and divide by 4.

The expression is:

  • Average =  [ 1.34 °C + (- 5 / 7 °C) + ( - 0.75 °C) + 4/9 ° C ] / 4

<u>3) Write the steps to solve the expression:</u>

You can choose between adding  fractions or adding the decimal forms of the numbers.

If you choose adding decimals, keep the complete decimals in your calculator, to avoid the accumulation of errors due to rounding. Round only the final result.

These are the steps.

<u>a. Find the decimal forms of the fractions:</u>

  • - 5/7  ≈ 0.71428
  • 4 /9 ≈ 0.44444

<u>b. Add the four data:</u>

  • 1.34°C + (- 0.71428 °C) + (-0.75 °C) + 0.44444 °C ≈ 0.32019 °C

<u />

<u>c. Divide the sum by the number of data (4)</u>

  • 0.32019 °C / 4 ≈ 0.080004 °C

<u>4. Round to the nearest hundredth</u>

The place of the hundreth is the second after the decimal point, which is 8 in this case:

  • 0.080004 °C ≈ 0.08 °C

7 0
3 years ago
If it is 5 F outside and the temperature will drop 17 F in the next six hours , how cold will it get?
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It will be as cold as -12 degrees Fahrenheit
(That’s pretty cold....)
That’s because 5 - 17= -12
Hope this helps :)
3 0
3 years ago
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so the answer is 60
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3 years ago
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Lorico [155]
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4 years ago
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Which of the following is the correct expansion of (3x-y)2
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\bold{[ \ Answer \ ]}

\boxed{\bold{9x^{2} \ - \ 6xy \ + y^{2} }}

\bold{[ \ Explanation \ ]}

  • \bold{Find \ Expansion: \ (3x \ - \ y^{2} )}

\bold{----------------------}

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\bold{\left(3x\right)^2-2\cdot \:3xy+y^2}

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= \bold{9x^2-6xy+y^2}

\boxed{\bold{[] \ Eclipsed \ []}}

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