Jawaban:

x = pinsil

y = buku

z = penghapus

pers

x + 2y + z = 6500........(1)

2x+y + 2z = 7000........(2)

2x+2y+z = 8000..........(3)

pers 1 dan 2

x + 2y + z = 6500.........×2

2x+y + 2z = 7000.........×1

-----------------------------

2x +4y + 2z = 13.000

2x+ y + 2z = 7000

---------------------------------(-)

3y = 6.000

y = 2.000

pers 1 dan 3

x + 2y + z = 6500.......x2

2x+2y+z = 8000........x1

--------------------------------

2x + 4y + 2z = 13.000

2x + 2y + z = 8000

--------------------------------(-)

2y +z = 5000.................1

2y + z = 5000

2(2000)+z =5000

z = 5000-4000

z = 1000

pers1

x + 2y + z = 6500

x +2(2000)+1000=6500

x +5000=6500

x = 6500-5000

x = 1500

jdi harga pinsil = 1500

buku = 2000

penghapus = 1000