If a sum of LE is to be changed into
44 banknotes which have the values of piastres and piastres, find the number of the banknotes needed from each type.
Let the number of banknotes with a value of 25 piastres be denoted
by and the number of banknotes with a value of 50 piastres be
denoted by . Then the equation for the number of each note is
Since is equivalent to
, therefore the equation for the value of
the notes is
Dividing by 25 gives
This pair of equations can be solved using the omitting method.
Subtracting the two equations gives
Substituting this value of into the first equation gives
Therefore, there are 8 notes of 25 piastres and 36 notes of 50