Having difficult time solving equation 4/(8 + 2w) = 7 for value of w

[Krack]

Good day friends.

Kindly help me understand what I am doing wrong with the following question.

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Solve the following:

. . . . .\(\displaystyle \dfrac{4}{8\, +\, 2w}\, =\, 7\)

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The answer I got was w = -26 but the answer in workbook states it should be w = -3.715

​Thank you for your help.

 

[mmm4444bot]

Kindly help me understand what I am doing wrong with the following question.

How can we see what you did wrongly, when we cannot see what you did?!

4
-------- = 7
8 + 2w

The answer I got was w = -26 but the answer in workbook states it should be w = -3.715

The book should not have the answer printed like that.

w does not equal -3.715

-3.715 is a rounded approximation (the exact answer is Rational).

The answer ought to have been stated as:

w = -3.715 (rounded)

or

w ≈ -3.175

Symbol ≈ means "is approximately equal to"

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Please show your work.

Also, please read the forum guidelines.

Thank you! :cool:

 

[mmm4444bot]

:idea: Another way to report the exact decimal-form of a Rational number, when that form contains a repeating digit (or group of digits), is to draw a horizontal bar over the repeating part.

So, the book could have also used this notation:

\(\displaystyle w = -3.\overline{714285}\)

 

[mmm4444bot]

Oh, another thought. :cool:

If the exercise includes instruction similar to, "Round your answer to the nearest thousandth", and you forgot to tell us this, then the book's answer is acceptable.

 

[mmm4444bot]

Okay -- I need to leave for work. Please post your work, so that somebody else can help you.

The following is my guess!

Maybe you forgot to multiply 7 times 2w, when using the Distribution Property. That mistake would lead to w = -26.

 

[Krack]

Yes. You are absolutely right.

I was just multiplying everything by numbers, but should of used. D-property.

Thank you very much for your help.