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.
Answer:
The cost of 1 postcard is $0.12 and the cost of 1 large envelop is $1.58.
Step-by-step explanation:
Let x be the cost of the postcard and y be the cost of the large envelop.
First customer paid $12 for 34 postcards and 5 large envelopes.
So, 34x + 5y = 12 --- (1)
Second customer paid $24.80 for 10 postcards and 15 large envelopes.
So, 10x + 15y = 24.8 --- (2)
Multiply the first equation by 3, we get,
(1) × 3 implies 102x + 15y = 36
(2) implies 10x + 15y = 24.8
Subtracting, we get,
92x = 11.2
x = 0.12
Substitute in (1), we get,
34(0.12) + 5y = 12
4.08 + 5y = 12
5y = 12 - 4.08
5y = 7.92
Divide both sides by 5.
y = 1.58
Hence, the cost of 1 postcard is $0.12 and the cost of 1 large envelop is $1.58.
