Answer :
20 water bottles because 5×4=20 so 60-20=40 so you divide 40 by 2 to get 20
2w+5j=60
2w+5(4)+60
2w+20=60
subtract 20 from both sides
2w=40
divide 2 from both sides
w=20
check
2(20)+5(4)=60
40+20=60
60=60
so if j=4 then w=20
2w+5(4)+60
2w+20=60
subtract 20 from both sides
2w=40
divide 2 from both sides
w=20
check
2(20)+5(4)=60
40+20=60
60=60
so if j=4 then w=20