Answer :
Bob age =x
Mary age= x+5
If we sum the ages
x+(x+5)=39
2x+5=39
then we clear x
2x=39-5
2x=34
x=34/2
x=17
Bob age =17
Mary age=17+5=22
Bob age =x
Mary age= x+5
If we sum the ages
x+(x+5)=39
2x+5=39
then we clear x
2x=39-5
2x=34
x=34/2
x=17
Bob age =17
Mary age=17+5=22