Answer:
The cost of postcard is $0.122 and the cost of large envelope is $1.57.
Step-by-step explanation:
Let, the cost of postcards = x and the cost of large envelopes = y.
According to the question, we get the following system of equations,
34x + 5y = 12
10x + 15y = 24.80
We will now solve this system to obtain the value of x and y.
First, we divide second equation by 5,
34x + 5y = 12
2x + 3y = 4.96
Now, we multiply second equation by 17,
34x + 5y = 12
34x + 51y = 84.32
Subtracting the equations gives us,
-46y = -72.32 i.e. y = 1.57.
Substituting the vale of y in the first equation gives us,
34x + 5 × 1.57 = 12 i.e. 34x + 7.85= 12 i.e. 34x = 4.15 i.e. x = 0.122.
Hence, the cost of postcard is $0.122 and the cost of large envelope is $1.57.
