George is making 8 gallons of tropical trip punch. he has already poured in 1 and 3/4 gal of pineapple juice and 2 and 1/2 gal of orange juice. the only other ingredient is 7-up. how much 7-up does george need?

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^