8x= 1000-440
8x=560
x=70
2. The number of Kobayashi stamps+the number of Xiaojun stamps = the total number of stamps.
Solution: If there are X Kobayashi, then there are 3x small armies.
x+3x=240
4x=240
x=60
3x= 180
3. Number of banyan trees+number of pine trees = total number of trees.
Solution: If there are x banyan trees, there are 2x pine trees.
x+2x= 120
3x= 120
x=40
2x=80
4. Number of roosters+number of hens = total.
Solution: If there are X cocks, there are (2x+30) hens.
x+(2x+30)=480
3x+30=480
3x=450
x= 150
2x+30=330
5. Stored grain in warehouse A = stored grain in warehouse B..
Solution: If warehouse B originally stored X tons of grain, warehouse A originally stored 3 tons of grain.
3x-90=x- 10
2x=80
x=40
3x= 120
6. Total sugar = total sugar
Solution: Let's have X children.
6x+80=8x-20
100=2x
x=50
50× 6+80 = 380 (piece)