2. If the decimal point is moved one place to the right, it becomes 10 times, so let the original number be x, 10x-x=2.7, and the result is x=0.3, so this number is 0.3.

3. Right

4. First shift the term in the equation1/3x =14/35-80/35 =-66/35 twice and then multiply it by 3, x=- 198/35.

5.2002/2003

6.89x 36/35x7=89x 36/5=3204/5

7. The working speeds of A, B and C are11012115, respectively. Now the amount of A and B completed is 4 (1/.

The remaining workload is 1-22/30=8/30, and the working time of Party C is (8/30)/(115) = 4 days.

8. First of all, in the same time, the ratio of distance is equal to the ratio of speed.

When the speed ratio of Party A and Party B is 5: 4 and the distance ratio of Party A and Party B is 5: 4 when they meet, then the remaining distance ratio of Party A and Party B is 4: 5 (you will understand this suggestion immediately by drawing a picture).

After the encounter, the speed ratio between Party A and Party B is 4: 4.8, so obviously, when Party A runs the remaining "4 x" distance, Party B only runs the remaining "4.8x" distance, and there is still "0.2x", which is 10km x = 50k m.

And a * * * from a to b is "4x+5x=9x", 9x = 450km.

It is highly recommended to draw a picture of this topic, which is clear at a glance.

If you don't understand, you can ask O(∩_∩)O~