3/2 - 5/7
find the common denominator. what is the lowest number that is divisible by both 2 and 7.
you want the fractions to have the same denominator in order to subtract them here. so in this case the most common denominator is 14 as it is both divisible by 2 and 7. now that we found that the next step is multiplying the denominator and the numerator by the number that gives us 14 in the denominator. so for 3/2 we would multiply by 7/7 and that would give us 21/14. now do that again for the 5/7 fraction. multiply denominator and numerator by the number that gives the a 14 in the denominator.
\[\left( \frac{ 3 }{ 2 }*\frac{7}{7} \right)-\left( \frac{ 5 }{ 7 }*\frac{ 2 }{ 2 } \right)=\frac{ 21 }{ 14 }-\frac{ 10 }{ 14 }\] now it's as simple as subtracting 21 from 10. you'll have a negative number.
whoops. sorry. worded that incorrectly. it should read, "...it's as simple as subtracting 10 from 21." you're answer will not be negative.
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