@ @QPS@ @pý†bɾa@ @ 120x + 100y = 8000 () 180x + 120y − (120x + 100y) = 0.38 × 8000 ( ) 60x + 20y = 3040 ( ) −2 ( ) 60y = 1920 y = 1920 = 32 60 () 120x + 100(32) = 8000 120x = 8000 − 3200 120x = 4800 . x = 40