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