home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Fractions Made Easy
/
WindowsFractions.iso
/
fraction
/
help2m
< prev
next >
Wrap
Text File
|
1995-01-03
|
2KB
|
67 lines
65
êêïMULTIPLYING FRACTIONS, INTERMEDIATE LEVEL
è In this section we will be looking at multiplying positive and/or
negative fractions.ïYou recall in the Elementary Level that when you
multiplied two positive fractions, you always got a positive fraction
as an answer.ïIn this section we are really considering multiplying
any fraction, positive or negative, times any other fraction, positive
or negative.ïThere will be two rules to cover the different cases.
The first rule is used when multiplying two fractions that are both
positive or both negative.ïThe second rule will be for multiplying two
fractions with different signs.ïThe following list shows the set of all
fractions.
êêêêïFractions
#êë ... -╩ï-╔è╚è╔è╩è╦è╠è═è╬ ...
êêè 1è1è1è1è1è1è1è1è1
#êë ... -╩ï-╔è╚è╔è╩è╦è╠è═è╬ ...
êêè 2è2è2è2è2è2è2è2è2
#êë ... -╦ï-╔è╚è╔è╩è╦è╠è═è╬ ...
êêè 3è3è3è3è3è3è3è3è3
êêêê.
êêêê.
êêêê.
Rule 4)ïTo multiply two fractions that are both positive,ïyou should
multiply them like we did in the Elementary Level.ïTo multiply two
fractions that are both negative, just multiply the two numerators and
the two denominators remembering that the product or quotient of two
negative numbers is positive.ïThen, cancel like factors and simplify.
Examples
ï1) Both fractions positive.
ê 5è 9ê 5∙9êè 5∙3∙3êë1êè1
#ê── ∙ ──è=è─────è=è ─────────è =è ───è =è ─
ê12è15ê12∙15ê 2∙2∙3∙3∙5êï2∙2êï4
2) Both fractions negative.
è -2è-3ë -2 ∙-3ê 6êè 2∙3êë1êè1
#è ── ∙ ──è=è─────è=è───è=è─────────è=è─────è=è──
ë9è 8ê9 ∙ 8ê9∙8ê3∙3∙2∙2∙2ê3∙2∙2ê12
Rule 5)ïTo multiply two fractions that have different signs, just
multiply the two numerators and the two denominators remembering that
the product or quotient of a positive number and a negative number is
negative.ïThen, cancel like factors and simplify.
3) One fraction positive and the second fraction negative.
êê2è-3ê2∙(-3)ê2∙(-3)ê-3
#êê─ ∙ ──è=è──────è=è──────è=è──
êê7è10ê 7∙10êï7∙2∙5ê35
4) The first fraction negative and the second fraction positive.
êë -1è12ê-1∙12ê-1∙2∙2∙3ê-3
#êë ── ∙ ──è=è─────è=è────────è=è──
êê4è 5ê 4∙5êè2∙2∙5êï5