Harga 8 pensil dan 3 penghapus 12.000.Harga 2 pensil dan 7 penghapus 17.500.Buatlah model matematikanya?

Pensil = x
penghapus = y

8x + 3y = 12.000 |x1| 8x + 3y = 12.000
2x + 7y = 17.500 |x3| 8x + 21y = 52.500
—————————————————— –
===================> -18y = -40.500
===================> y = -40.500 / -18
===================> y = 2.250

2x + 7y = 17.500
2x + 7(2.250) = 17.500
2x + 15.750 = 17.500
2x = 17.500 – 15.750
2x = 1.750
x = 1.750 / 2
x = 875