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Trouble Using a Cas Calculator

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Im Using a Cas Calculator to work out the Following Equation

x+11 2(x+14x)
------- = ---------
3 9

Now i no the Answer is -5 but when putting the following Equation in my Calculator i keep comimg up with

11
x= ----
9

Just looking for a bit of Help if any one can help me at all.. thanks Matt

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Are you sure it equals -5? I worked it out manually and came to the same answer as your calculator and substituting -5 in for x gives 2 = -16.67 which obviously is incorrect.

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this is the equation im doing, but my text book says its -5

Edited by Finalshine
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Textbooks often contain typos. You should solve the equation by hand and see what you find.

At the very least, try plugging in -5 and then 11/9, as hypervalent_iodine did, and see which value results in a true statement.

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I also got 11/9.

(x+11)/3=2(x+14x)/9

(x+11)/3=2(15x)/9

(11/9+11)/3=2(15(11/9))/9

(11/9+99/9)/3=2(55/3)/9

110/9/3 = 110/3/9

110/27 = 110/27

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Hang on Hang on. What sort of text book writes 30x as 2(x+14x)?!

I would bet a pound to a penny that it is not the answer which is wrong but the equation - either in the printing of the text or in the transcription

$\frac{x+11}{3}=\frac{2(x+14x)}{9}$

is awful similar to

$\frac{x+11}{3}=\frac{2(x+14)}{9}$

which is a much more normal way of writing things

$\frac{x+11}{3}=\frac{2(x+14)}{9}$

$\frac{9(x+11)}{3}=2(x+14)$

$3(x+11) = 2(x+14)$

$3x +33 = 2x +28$

$3x-2x = 28-33$

$x = -5$

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Hang on Hang on. What sort of text book writes 30x as 2(x+14x)?!

I would bet a pound to a penny that it is not the answer which is wrong but the equation - either in the printing of the text or in the transcription

$\frac{x+11}{3}=\frac{2(x+14x)}{9}$

is awful similar to

$\frac{x+11}{3}=\frac{2(x+14)}{9}$

which is a much more normal way of writing things

$\frac{x+11}{3}=\frac{2(x+14)}{9}$

$\frac{9(x+11)}{3}=2(x+14)$

$3(x+11) = 2(x+14)$

$3x +33 = 2x +28$

$3x-2x = 28-33$

$x = -5$

I was originally thinking that the book was going into simplification(combining like terms) because it was weird how a textbook would present the equation as such. Good eye, I must say.

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