Mark R. answered • 01/15/17

Charlotte based tutor - Adjunct Professor/Attorney/MBA/Engineer

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!**