Question 1117295
At the start
CARLOS
2x

DAVID
x



The $12 transfer from Carlos to David:
{{{2x-12=10+(x+12)}}}
{{{2x-12=x+22}}}
{{{2x=x+22+12}}}
{{{2x=34}}}
{{{x=34}}}


David originally had 34 dollars.
Carlos originally had 68 dollars.
Combined:  $102