Elimination Method: Jim bought 3 boxes of pencils and 2 boxes of pens for $6. He then bought 2 boxes of pencils and 4 boxes of pens for $8. Find the cost of each box of pencils and each box of pens.

Answer 1

let x = pencils

let y = pens

3x + 2y = 6

2x + 4y = 8

multiply the first equation by -2

-6x -4y = -12

2x + 4y = 8

add equations

-4x = -4

x = 1

plug in x into one of the equations

3(1) + 2y = 6

3 + 2y = 6

2y = 6

y = 3

$1 for pencils

$3 for pens