Solution: Suppose the original plan is to plant X trees every day, but actually X * (1+1/3) is planted every day {I will work it out for you directly =4X/3.

Simplification of the right side of 480/X-4=480/ 4X/3 equation

480/X-4=360/X shift term subtraction

(480-360)/X=4

4X= 120

X=30

Test: substitute X=30 into 480/x= 16.

So X=30 is the solution of the equation.

Solution: The original plan took 4 days longer than the actual task, and the number of days required in the original plan was 480/X, because the actual factory was 1/3 more than the planned factory, so the actual factory was (X+X* 1/3), which can be obtained.

I plan to plant 30 trees every day.