Question 835994
b beef
p pork
y soY
w water as ice


{{{b+p+y+w=600}}}



Account for Protein: {{{0.2b+0.1p+0.9y+0*w=0.15}}}

Account for Moisture:  {{{0.67b+0.4p+0.07y+1*w=0.60}}}

Account for Fat:  {{{0.13b+0.5p+0*y+0*w=0.25}}}


This is a linear system of four equations in four unknown variables.  The ingredient accounting equations should be adjusted so whole number coefficients.  You would probably choose to use matrix operations to solve the system.  ( I myself would try to use some on-line matrix software to handle the system, like the one through purdue ).