في النظام الخطي التالي :
begin mathsize 18px style
open curly brackets table attributes columnalign left end attributes row cell bold minus bold 2 bold x bold space bold plus bold space bold y bold equals bold 5 end cell row cell bold 3 bold x bold minus bold space bold 4 bold space bold y bold equals bold minus bold 25 end cell end table close end style
نجد أن محدد المتغير begin mathsize 18px style bold italic y end style والذي يرمز له بالرمز begin mathsize 18px style bold increment subscript bold y end style يساوي:
begin mathsize 18px style capital delta subscript y equals space open vertical bar table row cell negative 2 end cell 1 row 3 cell negative 4 end cell row blank blank end table close vertical bar space equals space space 5 end style
capital delta subscript y space equals space open vertical bar table row cell negative 2 end cell 5 row 3 cell negative 25 end cell row blank blank end table close vertical bar space equals space 35
capital delta subscript y space equals space open vertical bar table row 5 1 row cell negative 25 end cell cell negative 4 end cell row blank blank end table close vertical bar space equals space 5
capital delta subscript y space equals space open vertical bar table row 2 cell negative 1 end cell row 3 cell negative 4 end cell row blank blank end table close vertical bar space equals space minus 5
