Let the number of large chairs be x and small chairs be y
40x + 30y = 26 x 60 = 1,560 . . . . (1)
80x + 75y = 57 x 60 = 3,420 . . . . (2)
(1) x 2 => 80x + 60y = 3,120 . . . . (3)
(2) - (3) => 15y = 300 => y = 300/15 = 20
From (2), 80x + 75(20) = 3,420 => 80x + 1,500 = 3,420 => 80x = 3,420 - 1,500 = 1,920 => x = 1,920/80 = 24
Therefore, the company should produce 24 large chairs and 20 small chairs.