Qunyi furniture factory sells 1 / 5 of the five drawer cabinets, 120 less than the five drawer cabinets. How many bookcases and five drawer cabinets are sold? Make a cuboid with a volume of 60 cubic decimeters. The bottom is 4 decimeters long and 3 decimeters wide. How many decimeters high should it be? Dongxiang agricultural machinery plant has 39 tons of coal, which has been burned for 16 days, with an average of 1.2 tons per day. If the rest is less than 1.1 tons per day, how many days can it be reduced? The above problems are solved by equations_ ∩) O... Ha ha

Qunyi furniture factory sells 1 / 5 of the five drawer cabinets, 120 less than the five drawer cabinets. How many bookcases and five drawer cabinets are sold? Make a cuboid with a volume of 60 cubic decimeters. The bottom is 4 decimeters long and 3 decimeters wide. How many decimeters high should it be? Dongxiang agricultural machinery plant has 39 tons of coal, which has been burned for 16 days, with an average of 1.2 tons per day. If the rest is less than 1.1 tons per day, how many days can it be reduced? The above problems are solved by equations_ ∩) O... Ha ha

1. Suppose five drawer cabinet X and bookcase y, then y = x / 5, x = y + 120, x = 150, y = 30
2. Let the height x, then 4 * 3 * x = 60, x = 5
3. Let x day 1.1 x + 1.2 * 16 = 39, x = 18