SOLUTION: I subtracted {{{7&3/4}}} - {{{3&5/6}}} and I came up with {{{4&1/12}}} but that was not right can u help me?

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: I subtracted {{{7&3/4}}} - {{{3&5/6}}} and I came up with {{{4&1/12}}} but that was not right can u help me?       Log On


   

Question 519261: I subtracted 7%263%2F4 - 3%265%2F6 and I came up with 4%261%2F12
but that was not right can u help me?

Found 2 solutions by stanbon, Edwin McCravy:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
I subtracted 7 3/4 from 3 5/6 and i came up with 4 1/12.
----------------------
3 5/6 - 7 3/4
Convert to fraction form:
---
= (6*3+5)/6 - (4*7+3)/4
---
= 23/6 - 31/4
Establish a common denominator:
---
= (46/12) - (93/12)
---
= -47/12
Convert to mixed-number form:
---
= -3 11/12
==========
Cheers,
Stan H.

Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!

This is the way they teach you to do it in most schools.
Do not change mixed numbers to improper fractions when
adding and subtracting but leave them as mixed numbers
like this:


   73%2F4 =  79%2F12 =  621%2F12 
  -35%2F6 = -310%2F12 = -310%2F12 
------------------------------ 
                311%2F12

Notice in the last step the 7 was changed to 6 and the fraction was changed by
adding 12 to the numerator.  In other words, we "borrowed" 1 from the 
7, and called it 12%2F12ths and added it to the fraction 9%2F12 and got
21%2F12, so we'd have a larger fraction on top.   

Edwin