Mariko and her friend spent $24.50 on lunch. Their lunches cost the same amount,
and they used a $4 off coupon. Determine
the cost of each lunch. ​

The cost: $14.25

Equation: 24.5=2c-4

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations:

the formula of a slope:

we have the points (-2, 7) and (2, 3). substitute: