(31/3+2,5)×(4,6-21/3)
(31/3+2,5)×(4,6-21/3) (31/3+25/10)×(4,6-7) (31/3+5/2)×(-2,4) 62+15/6×(-2,4) 77/6×(-2,4) -77/6×24/10 -77×4/10 -77×2/5 -154/5