I need help plz .

1.42

Step-by-step explanation:

A. Each large envelope costs $1.42

Step-by-step explanation:

To solve this, we want to set up a system of equations.

The first customer paid $12 for 14 postcards & 5 large envelopes.

The second customer paid $24.80 for 10 postcards & 15 large envelopes.

Now let's set up our equations together.

14p + 5e = 12

10p + 15e = 24.80

We will solve this through elimination. First we want to eliminate one variable at a time. We will start with e because we can see that 5 and 15 will simplify easily.

Multiply the first equation by -3 to cancel out the variable e.

-3(14p + 5e = 12) = -42p - 15e = -36

Now set this up for elimination.

-42p - 15e = -36

10p + 15e = 24.80

-32p = -11.2

Divide both sides by -32.

p = 0.35

Each postcard costs $0.35.

Now that we know the value of p, let's plug it into one of equations to find e.

14p + 5e = 12

14(0.35) + 5e = 12

4.9 + 5e = 12

5e = 7.1

e = 1.42

Each large envelope costs $1.42

Check your answer by plugging both values back into the equation you haven't used yet.

10p + 15e = 24.80

10(0.35) + 15(1.42) = 24.80

3.5 + 21.3 = 24.80

24.80 = 24.80

Your answer is correct.

Hope this helps!

stop cheating

step-by-step explanation:

step-by-step explanation:

mean or average is 40.6