Question 971141
c=chicken  p=pasta

c + p=240
12c + 8p=2100

multiply top by (-8)
-8c - 8p =-1920
12c + 8p=2100

4c = 180
c=45
p=195

cost for c=45*12=540
cost for p= 195 *8=1560
sum is 2100.