Answer :
6 is the missing factor.
30 plus 12 is 42. If we do 6 times 5 that is 30. Then 6 times 2 is 12. If we add 30 and 12 we get 42, making the expression true.
30 plus 12 is 42. If we do 6 times 5 that is 30. Then 6 times 2 is 12. If we add 30 and 12 we get 42, making the expression true.