Because there is a limited amount of compost with a limited amount of minerals. In the garden there is loads of soil and loads of minerals. because of decomposition and absorption minerals can easily be replaced in the garden soil, unlike in a plant pot.
Simple
Nine less than a number times four equals fifteen
basically, x*4-9=15 would be your equation, or something similar
Well, we know x can't equal 1,2,3,OR 4. Five is also out, because 5*4=20-9=11, so cross that out.
But if you try doing 6*4-6=15, it fits.
6*4=24, 24-9=15
Thus, x=6, so your answer to Nice less than four times a number equals fifteen is 6.
~Hope this helps!
