Question #42209

1 Answer
Nov 7, 2017

3

Explanation:

#color(blue)("Preamble")#

A fractions structure (using description ) is

#("count")/("size indicator of what you are counting") ->("numerator")/("denominator")#

#color(brown)("You can not "ul("DIRECTLY")" add, subtract or divide")##color(brown)("the counts unless the 'size indicators' are the same.")#
#color(white)()#

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#color(blue)("Answering the question")#

Consider: #a-:b#. The dividend is #a#

I am assuming the interpretation of your question is

#1 1/2" dividend by " 1/2#

#1 1/2color(white)("dddd") -: color(white)("ddddd")1/2#

Note that #1 1/2# is the same as #3/2# so we have:

#3/2-:1/2#

There are two approaches.

#color(brown)("Approach 1:")#

As the bottom numbers (numerators) are the same we can just divide the top numbers and totally forget about the bottom ones.

#color(brown)("Approach 2: - shortcut method")#

Turn the #1/2# upside down and multiply

#3/cancel(2)^1xxcancel(2)^1/1color(white)("d")=color(white)("d")3/1=3#

Notice that the two's completely cancel out confirming Approach 1

The shortcut method works when the denominators are not the same. Explaining why is not provided as I do not wish to confuse you.