Question

The school store sells pencils and erasers.

Answer 1

Answer:

$0.18

Step-by-step explanation:

we need to set up two simultaneous equations

using variables, pencils = p and erasers = e

3 pencils and 2 erasers, the cost is $0.76

3p + 2e = $0.76

2 pencils and 4 erasers, the cost is $1.04.

2p + 4e = $1.04

we now have

3p + 2e = $0.76

2p + 4e = $1.04

to make the number of erasers the same, multiply the first equation by 2 to give 4e

2(3p + 2e = $0.76)

6p + 4e = $1.52

now we have the same number of erasers for both equations

6p + 4e = $1.52

2p + 4e = $1.04

subtract across: 6p - 2p = 4p, 4e - 4e = 0, $1.52 - $1.04 = $0.48

we are left with 4p = $0.48

divide both sides by 4

p = $0.12

1 pencil = $0.12

go back to the start of both equations and use one of them to find 1 eraser. I'll use 3p + 2e = $0.76

input $0.12 in p

3($0.12) + 2e = $0.76

$0.36 + 2e = $0.76

subtract $0.36 on both sides

2e = $0.76 - $0.36

2e = $0.40

divide 2 on both sides

e = $0.20

1 eraser = $0.20

How much more does 1 eraser cost than 1 pencil?

we now know 1 pencil = $0.12 and 1 eraser = $0.20

find the difference between them

$0.20 - $0.12 = $0.18

final answer= $0.18