Answer:
The cost of the 1 muffin is $1.5 and 1 quart of milk cost is $3 .
Explanation:
Let us assume that the cost of one muffins be x.
Let us assume that the cost of one 1 quarts of milk be y.
As given
The cost of 8 muffins and 2 quarts of mil is $18.
Than the equation becomes
8x + 2y = 18
As given
The cost of 3 muffins and 1 quart of milk is $7.50.
Than the equation becomes
3x + 1y = 7.50
Two equations are
8x + 2y = 18 and 3x + 1y = 7.50
Multiply 3x + 1y = 7.50 by 2 and subtracted from 8x + 2y = 18 .
Thus
8x - 6x + 2y - 2y = 18 - 15
2x = 3
x = 1.5
Put x = 1.5 in 3x + 1y = 7.50
3 × 1.5 + y = 7.50
y = 7.50 - 4.5
y = 3
Therefore the cost of the 1 muffin is $1.5 and 1 quart of milk cost is $3 .