Question 1005930
Unit for rate is SACKS per WEEK.  Call their capital letters their corresponding rates.

Any combination of machines working at the same time is the sum of their rates.
{{{system(A+B+C=114,A+B=68,B+C=84)}}}


Solve the system any way you want or need.


Here is a possible way.
{{{A=114-B-C}}}
-
{{{system((114-B-C)+B=68,B+C=84)}}}

{{{114-B-C+B=68}}}
{{{114-C=68}}}
{{{114-68=C}}}
{{{highlight(C=46)}}}


{{{B+C=84}}}
{{{B=84-C}}}
{{{B=84-46}}}
{{{highlight(B=38)}}}


You can find A from those values.
{{{highlight(A=30)}}}