Given:
Leander planted 100 acres with soybeans and he plans to increase his field size by 3% each year.
Let the total planted acres = y, and the number of years = x
The initial planted acres = 100
the rate of increase the planted acres = 3% = 0.03
So, the relation between x and y will be as follows:

We will find the number of years (x) required to reach y = 250 acres
so, substitute y = 250 and then solve for x:

So, the answer will be the number of years = 31