Lingling exercised very early. One day, he set out from home and ran to the park. At this time, it is still 800 meters away from the park, and he has finished one third of the whole course. At this time, the running distance ratio is 4: 1, and her home is away from the park1500m.

Calculate the formula according to the meaning of the question:

4/(4+ 1)=4/5

800÷[ 1-(4/5- 1/3)]

=800÷[ 1-7/ 15]

=800÷8/ 15

= 1500 (m)

So her home is 0/500m away from the park/kloc-.

Mixed operation:

If the first-level operation and the second-level operation exist at the same time, the second-level operation is calculated first. If there are one, two and three operations at the same time (i.e. power, root and logarithm operations), the third operation is calculated first, and then the other two levels are calculated.

If there are brackets, count the numbers in brackets first (no matter what level, count first) The third level should be counted in brackets, and then the second and first levels should be counted.