Question

In a recent year, a letter to Europe from the United States costs $0.94 to mail. A letter mailed within the United States costs $0.44. Nancy mailed 5 letters for $3.70, some to Europe and some to the United States. How many letters did she send to Europe

Answer 1

she send 3 letters to Europe and 2 within the USA
3 letter to Europe=2.82
2 letters to USA = 0.88
2.82+0.88=3.70

Answer 2

Answer:

3 to Europe

Step-by-step explanation:

Let x represent the number of letters sent to Europe and y represent the number of letters sent to the U.S.

$0.94 for each letter sent to Europe gives us the expression 0.94x.

$0.44 for each letters sent to the U.S. gives us the expression 0.44y.

Together the total was $3.70; this gives us the equation

0.94x+0.44y = 3.70

There were 5 total letters sent; this gives us the equation

x+y = 5

This gives us the system

$\left \{ {{0.94x+0.44y=3.70} \atop {x+y=5}} \right.$

We will use substitution to solve this; we will isolate the variable x in the second equation.  We can do this by subtracting y from each side:

x+y = 5

x+y-y = 5-y

x=5-y

Next we substitute this into the first equation:

0.94x+0.44y = 3.70

0.94(5-y)+0.44y = 3.70

Using the distributive property,

0.94(5)-0.94(y)+0.44y = 3.70

4.7-0.94y+0.44y = 3.70

Combining like terms,

4.7-0.5y = 3.70

Subtract 4.7 from each side:

4.7-0.5y-4.7 = 3.7-4.7

-0.5y = -1

Divide both sides by -0.5:

-0.5y/-0.5 = -1/-0.5

y = 2

There were 2 letters mailed to the U.S.

Substitute this into the second equation:

x+2 = 5

Subtract 2 from each side:

x+2-2 = 5-2

x = 3

There were 3 letters mailed to Europe.