9514 1404 393
Answer:
(x, y) = (2, -6)
Step-by-step explanation:
Subtract the first equation from the second.
(8x -2y) -(5x -2y) = (28) -(22)
3x = 6
x = 2
Substitute this into either equation and solve for y.
8(2) -2y = 28
8 -y = 14 . . . . . . . . divide by 2
y = 8 -14 = -6 . . . . add y-14 to both sides
The solution is (x, y) = (2, -6).
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I like a graphing calculator for a quick solution to such problems.
Assume that the cost of the milk is x.
We are given that a sandwich costs 0.75$ more than the cost of milk. This means that:
cost of sandwich = cost of milk + 0.75
cost of sandwich = x + 0.75
Now, the customer bought 4 sandwiches and 4 containers of milk at the cost of 7$.
We will transform this into an equation as follows:
total cost = cost of 4 sandwiches + cost of 4 containers of milk
7 = 4(x+0.75) + 4(x)
Solve the above equation to get x as follows:
7 = 4x + 3 + 4x
7-3 = 8x
8x = 4
x = 0.5
Therefore:
cost of milk = x = $0.5
cost of sandwich = x+0.75 = 0.5+0.75 = $1.25