Current location - Training Enrollment Network - Mathematics courses - The answers to questions 2-8 on P38 of the compulsory senior high school mathematics of Beijing Normal University Edition should be detailed (online, etc ...). If it is good, add 20 points.
The answers to questions 2-8 on P38 of the compulsory senior high school mathematics of Beijing Normal University Edition should be detailed (online, etc ...). If it is good, add 20 points.
8. Solution: The number of pebbles is 135...35, and there are (35-1)/2+1=18 items.

The distance is 1.47 ...

Then the final distance is1+(18-1) * 3 = 52m.

The distance from A to B is (1+52)* 18/2=477 m.

7. The line number is 1 3 5 7…, which is a arithmetic progression with a tolerance of 2.

Then line 20 has 1+(20- 1)*2=39.

The leftmost number in line 20 is 20*20-39+ 1=362.

The sum of all the figures in line 20 is (362+400)*39/2= 14859.