Question 735051
a for Alice
b for Bob
c for Carol


{{{a=b+2}}}, {{{b=2c}}}, {{{a+b+c=27}}}


Maybe two or more solution processes are possible.  Do a couple of substitutions for a least advanced solving method.  A fairly logical way could be substitute b into the first equation, use this result for a to substitute into the third equation.  Now, substitute the formula for b (from the second equation into the third equation).  You now have an equation with only c as the variable.  Finish solving.


What I described is this:

a=(2c)+2, 
The next substitution is into a+b+c=27,
(a)+b+c=27
(2c+2)+b+c=27
Following that, the next substitution using b is,
(2c+2)+(2c)+c=27
2c+2+2c+c=27
and you can finish this easily(?).