What you do is you will take the clock and make it into a protractor or put a protractor on the clock and then the protractor will say the angles
So all you do is you divide 2 1/2 by .25 and you get 10 then you know one fourth or 25% of that package is 10 berries so the rest or 30% left over is 30 berries.
4x=5x-12
subtract 5x from each side
-x=-12
to get a positive x multiply each side by a -1
x=12
Hope I helped :)