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Solve for X.

 

a/b(2x - 12) = c/d

 Aug 20, 2017
 #1
avatar+178 
+2

Input: Solve for X. a/b(2x - 12) = c/d

Intepretation: Solve for \(x\) in \(\frac{a}{b}(2x-12)=\frac{c}{d}\)

Solution:

Multiple both sides by \(bd\):

\(ad(2x-12)=bc\)

Expand:

\(2adx-12ad=bc\)

Move the numerical term to the right:

\(2adx=12ad+bc\)

Divide both sides by \(2\)
\(adx=6ad+\frac{bc}{2}\)

Finally, divide both sides by a factor of \(ad\):

\(x=6+\frac{bc}{2ad}\)

Done :)

 Aug 20, 2017
 #2
avatar+14995 
+2

Solve for X.
a/b(2x - 12) = c/d

1.                                            on both sides

\(\frac{a}{b}(2x - 12) = \frac{c}{d}\)                 [\(\times\frac{b}{a}\)

\(2x-12=\frac{bc}{ad}\)                      [+12       

\(2x=\frac{bc}{ad}+12\)                      [ / 2

\(x=\frac{bc}{2ad}+6\) 

 

2.

\(\frac{a}{b(2x-12)}=\frac{c}{d}\)                        [\(\times (2x-12)\) 

\(\frac{a}{b}=\frac{c}{d}(2x-12)\)                 [\(\times\frac{d}{c}\)

\(\frac{ad}{bc}=2x-12\)                      [+12

\(\frac{ad}{bc}+12=2x\)                      [ / 2

\(\frac{ad}{2bc}+6=x\)

\(x=\frac{ad}{2bx}+6\)

 

Both can be meant. Use brackets!

laugh  !

 Aug 20, 2017
 #3
avatar+178 
+2

Good work of yours! It is really easily for people to confuse others with inappropiate use of brackets.

Jeffes02  Aug 20, 2017
 #4
avatar+14995 
+1

If I mean \(\frac{a}{b}(2x-12)=\frac{c}{d}\), I should write (a/b)*(2x - 12) = c/d.

If I mean \(\frac{a}{b(2x-12)}=\frac{c}{d}\), I should write a/(b(2x - 12)) = c/d.
This is not unreasonable.

a/b(2x - 12) = c/d  can mean both.

asinus  Aug 20, 2017

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