2.(3 1)X26=(62)X( 13)
(2 1 )X36=63X( 12)
(32 )X69=96X(23)
4. Read 8 pages on the first day. From the next day, read 2 pages more than the previous day, so that the last day happens to be 16 pages.
Then the number of days of study is: (16-8)/2+ 1=5.
Don't look at pages 8, 10, 12, 14, 16 in these five days.
Total pages of the book: 8+10+12+14+16 = 60 pages.
5.◎+◎+◎+☆+☆= 14
☆+☆+◎+◎+◎+◎+◎= 18
Subtract the above formula with the following formula: (☆+☆+☆)-(☆+☆) =18-14.
Namely: ◎+◎=4
◎=2, and substitute it into the first formula: 2+2+2+☆+☆= 14.
☆=4.
So ◎=2, ☆=4.
6. A duck weighs two kilograms
A chicken is as heavy as two ducks, so a chicken: 4 kg.
Three chickens and a duck are as heavy as a pig. Pig: 4*3+2= 14 kg.
A panda is as heavy as two pigs. Panda: 14 * 2 = 28kg.
7. 1.2+8.7=9.9 1.3+8.6=9.9 1.4+8.5=9.9 1.5+8.4=9.9 1.6+8.3=9.9
1.7+8.2=9.9 2.8+7. 1=9.9 2.6+7.3=9.9 2.5+7.4=9.9 ...
8. Fill three glasses of water, and the bottle weighs 420g, that is, three cups+1 bottle = 420g.
; Fill it with five glasses of water, and the bottle weighs 600g, that is, 5 cups+1 bottle = 600g.
The following formula-the above formula: 2 cups = 600-420 =180g.
A glass of water = 90g.
Empty bottle = 420-90 * 3 = 150g