Basic Fraction Question

vonsmiley

New member
Joined
Jun 22, 2006
Messages
28
Hi everyone. If you are not tired of me I need a simple question answered.
:?: Fractions:

If you have a mixed number and the whole-number part is negative, is the fraction negative? Looking at this exercise:

. . .-2 <sup>3</sup>/<sub>4</sub> + -5 <sup>1</sup>/<sub>5</sub>
. . .-2 <sup>15</sup>/<sub>20</sub> + (-5 <sup>4</sup>/<sub>20</sub>)
. . .-7 <sup>19</sup>/<sub>20</sub> = ...

Here's where the question (above) comes in. Is it:

. . .-7 + 1 <sup>1</sup>/<sub>20</sub>, which equals 6 <sup>1</sup>/<sub>20</sub>

Or is it:

. . .-8 <sup>1</sup>/<sub>20</sub>
 

pka

Elite Member
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Jan 29, 2005
Messages
7,820
If you owe James $2.75, -2(3/4), and you owe Jane $5.20, -5(1/5), how much do you owe in all?
 

stapel

Super Moderator
Staff member
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Feb 4, 2004
Messages
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The negative is on the entire number. Note that juxtoposition, in the case of mixed numbers, actually indicates addition. That is:

. . . . .\(\displaystyle \L 4\,+\,\frac{1}{3}\,=\,4\frac{1}{3}\)

. . . . .\(\displaystyle \L -4\,-\,\frac{1}{3}\,=\,-4\,+\,-\frac{1}{3}\,=\,-4\frac{1}{3}\)

Subtracting:

. . . . .\(\displaystyle \L 4\frac{2}{3}\,-\,1\frac{1}{3}\,= \,\left(4\,+\,\frac{2}{3}\right)\,+\,\left(-1\,-\,\frac{1}{3}\right)\)

. . . . .\(\displaystyle \L =\,4\,-\,1\,+\,\frac{2}{3}\,-\,\frac{1}{3}\,=\,3\,+\,\frac{1}{3}\,=\,3\frac{1}{3}\)

Eliz.
 

vonsmiley

New member
Joined
Jun 22, 2006
Messages
28
:oops: but what if you have to use improper fractions to solve the problem I keep geting -7 11/20 which is wrong.................. what have I done to be cursed with math as a subject.
 

Sendell

New member
Joined
Aug 7, 2006
Messages
17
vonsmiley said:
Hi everyone. If you are not tired of me I need a simple question answered.
:?: Fractions:

If you have a mixed number and the whole-number part is negative, is the fraction negative? Looking at this exercise:

. . .-2 <sup>3</sup>/<sub>4</sub> + -5 <sup>1</sup>/<sub>5</sub>
. . .-2 <sup>15</sup>/<sub>20</sub> + (-5 <sup>4</sup>/<sub>20</sub>)
. . .-7 <sup>19</sup>/<sub>20</sub> = ...

Up to here you've done everything correctly. -7 19/20 is your final answer. Think of it as -(7 + 19/20), or -7.95
Here's where the question (above) comes in. Is it:

. . .-7 + 1 <sup>1</sup>/<sub>20</sub>, which equals 6 <sup>1</sup>/<sub>20</sub>

Or is it:

. . .-8 <sup>1</sup>/<sub>20</sub>
 
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