Ineed with 19, 20, and 21! and you!

19) because 1/2 an hour is 8 miles, 1 hour will take 16 miles , multiply 8 by 2 because I️t gave half an hour so multiplying by 2 will give an hour (2 half’s make a whole)

20) 2 1/2 multiplied by 4 is 10, so his jog will be 10 minutes longer

21) 4,500 was what he earned and 4,900 was what he lost (“expenses”) so he lost $400:
$4,500 - $4,900= -$400
He lost money because the answer is negative