How do you add #\frac { 11} { 12} + \frac { 7} { 9} + 3\frac { 1} { 2}#?

1 Answer
Oct 3, 2017

= #5\frac{7}{36}#

Explanation:

#\frac { 11} { 12} + \frac { 7} { 9} + 3\frac { 1} { 2}#

First convert the mixed number in improper fraction:

=#\frac { 11} { 12} + \frac { 7} { 9} + \frac {3\times2+ 1} { 2}#

=#\frac { 11} { 12} + \frac { 7} { 9} + \frac {7} { 2}#

Find the LCM of the denominators, i.e. LCM of 12, 9 and 2,
which is 36.

Now make the denominators equal so that the fractions can be added:

=#\frac { 11} { 12} (3/3)+ \frac { 7} { 9}(4/4) + \frac {7} { 2}(18/18)#

=#\frac { 33} {36} + \frac {28} { 36} + \frac {126} {36}#

Now add:

=#\frac { 33+28+126} {36} #

=#\frac { 187} {36} #

= #5\frac{7}{36}#