What number results when 8 is subtracted from a certain number and the result is multiplied by 3 to equal 21?

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Multiple Choice

What number results when 8 is subtracted from a certain number and the result is multiplied by 3 to equal 21?

Explanation:
To solve the problem, we need to set up an equation based on the information provided. Let the certain number be represented as \( x \). According to the question, when 8 is subtracted from this number \( x \), and the resulting value is then multiplied by 3, we get 21. This can be expressed mathematically as: \[ 3(x - 8) = 21 \] To find \( x \), we will first divide both sides of the equation by 3 to isolate \( x - 8 \): \[ x - 8 = \frac{21}{3} \] This simplifies to: \[ x - 8 = 7 \] Next, we add 8 to both sides to solve for \( x \): \[ x = 7 + 8 \] This results in: \[ x = 15 \] Thus, the number that fulfills the criteria of the question is 15. Therefore, it's correct to conclude that when 8 is subtracted from 15 and the result is multiplied by 3, it does indeed equal 21: \[ 3(15 - 8) = 3(7) = 21

To solve the problem, we need to set up an equation based on the information provided. Let the certain number be represented as ( x ).

According to the question, when 8 is subtracted from this number ( x ), and the resulting value is then multiplied by 3, we get 21. This can be expressed mathematically as:

[

3(x - 8) = 21

]

To find ( x ), we will first divide both sides of the equation by 3 to isolate ( x - 8 ):

[

x - 8 = \frac{21}{3}

]

This simplifies to:

[

x - 8 = 7

]

Next, we add 8 to both sides to solve for ( x ):

[

x = 7 + 8

]

This results in:

[

x = 15

]

Thus, the number that fulfills the criteria of the question is 15. Therefore, it's correct to conclude that when 8 is subtracted from 15 and the result is multiplied by 3, it does indeed equal 21:

[

3(15 - 8) = 3(7) = 21

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