Question 60209
15.40X+19.60Y=852.60
15.40X=852.60-19.60Y 
X=(852.60-19.60Y)/15.40 AND
15.40Y+19.60X=852.60-25.20
IF WE SUBSTITUTE (852.60-19.60Y)/15.40 FOR X IN THE SECOND EQUATION WE GET

15.40Y+19.60(852.60-19.60Y)/15.40=852.60-52.20
15.40Y+19.60/15.40(852.60-19.60Y)=800.4
15.40Y+1.2727(852.60-19.60Y)=800.4
15.40Y+1085.1272-24.94545Y=800.4
-9.54545Y=800.4-1085.1272
-9.54545Y=-284.7272
Y=-284.7272/-9.54545
Y=29.829 THUS THE NIGHT TIME HOURS WORKED
X=(852.6-19,60*29.829)/15.40
X=(852.6-584.648)/15.40
X=267.952/15.40
X=17.4 THUS THE DAY TIME HOURS WORKED