Question 703393
Picking variables,  x= how many snickers, y= how many reeses.  The total count of candies is x+y=12.


The fat -----
Combined, the amount of fat is 70+26.5 grams.  This is 96.5 grams of fat.


Use the variables and the fat content to account for the fat:
14*x+13.7*y=96.5


The system to solve is:
{{{14*x+13.7*y=96.5}}}
{{{x+y=12}}}
The easiest path to continue from here is to multiply the second equation by 14, and then subtract from the first equation.  This will lead you to a solution for y.   Then continue solving.