Question 309973
Well, think of 1 as {{{1/1}}}. So this means that {{{1/(1/3)=(1/1)/(1/3)}}}



So our goal is to simplify {{{(1/1)/(1/3)}}}



{{{(1/1)/(1/3)}}} Start with the given expression.



{{{(1/1)*(3/1)}}} Multiply the first fraction {{{1/1}}} by the reciprocal of the second fraction {{{1/3}}} (ie 'flip' the second fraction and multiply)



{{{(1*3)/(1*1)}}} Combine the fractions.



{{{3/1}}} Multiply



{{{3}}} Reduce.



So {{{1/(1/3)=3}}}. It turns out that {{{1/(1/x)=x}}} for any 'x' that is not zero. For instance, if {{{x=5}}}, then {{{1/(1/5)=5}}}. So this will save time in the future (hopefully you'll understand how it all works).



So {{{12&1/2+1/(1/3)}}} then becomes {{{12&1/2+3}}}. Does this help you get moving in the right direction?