Let x = "How many tons of beets are processed per day?", i.e. the value under the question.

Then the condition gives you this equation


     -  = 1,     (1)


which is direct translation of the condition to Math.


To simplify calculations, we can make an agreement that we measure the amounts not in tons, but in THOUSANDS of tons.

Then the equation (1) takes the form


     -  = 1.              (2)


Then I can solve it mentally:  x = 12.


Indeed,   -  =  = 6 - 5 = 1.


You can solve the equation (2) formally by multiplying both sides by x:


60*x - 60*(x-2) = x*(x-2),

60x - 60x + 120 = x^2 - 2x

x^2 - 2x - 120 = 0

(x - 12)*(x + 10) = 0.


Of the two roots  x= 12  and  x= -10  only positive root x= 12 satisfies the condition.


Answer.  12000 tons of beets are processed per day normally.