First, convert 3 into a fraction with denominator 8.
(3 pizzas)(8/8 pizzas)=24/8 pizzas
Then, divide 24/8 pizzas by 2/8 pizzas per 1 person.
(24/8 pizzas)(2/8 pizzas/person)
Dividing by a fraction is the same as multiplying by the reciprocal:
(24/8)/(2/8)=(24/8)×(8/2) the 8s cancel and you are left with 24/2=12
3 pizzas will feed 12 people.
7x-(x-y) = 7x - x + y = 6x + y
9a-(2b-a) = 9a+a-2b = 10a-2b
hope it helped