So you have to solve for "donation" - so let's call that X. And the things we know are what the grandfather donated, as a function - meaning based upon - Theo's donation. We'll call that Y.
So Y is equal to 1/2 of $4 plus Theo's donation...... 0.5*(x+4).
So... 4.25 = 0.5(X+4), solving for X
4.25=0.5x + 2
-2 -2
2.25=0.5x - divide each side by 0.5 to get x alone.
x = 4.50
Plugging back in:
(4.50 + 4.00)*0.5 = 4.25!
Let vons market receive x loaves. Then savemart received x+12 loaves and Ralphs received x + 12 + 6 = x + 18 loaves, Therefore:-
x + x + 12 + x + 18 = 180
3x + 30 = 180
3x = 150
x = 150/3 = 50
So vons received 50, savemart received 62 and ralph's received 68 loves. Answer