3 moer than (3+) 2 times the numbe of books he sold in the second week (2 times second week)
first week=3+(2 time 2nd week)
total ie sold 18
so
first week+second week=18
3+(2 times 2nd week)+2nd week=18
solve
minus 3 both sides
3-3+(2 times 2nd week)+2nd week=18-3
0+(2 times 2nd week)+2nd week=15
(2 times 2nd week)+2nd week=15
add
3 times 2nd week=15
divide both sides by 3
2nd week=5
sub back
first week+second week=18
first week+5=18
minus 5
first week=13
he sold 13 in the first week