Question 146207

Let X=the remaining number
Now we have:

V=(Z+Y+X)/3  multiply each side by 3
3V=Z+Y+X  subtract Z and also Y from each side

3V-Z-Y=Z-Z+Y-Y+X  collect like terms

3V-Z-Y=X or
X=3V-Z-Y-----------------the remaining number

CK
V=(Z+Y+3V-Z-Y)/3 or
V=V

Hope this helps---ptaylor