Question

C + m = 20
4c + 2m = 68

Answer 1

c= 20-m
4c+2m=68
4(20-m)+2m=68
80-4m+2m=68
-4m+2m=68-80
-2m= -12 (.-1)
2m= 12
m= 12/2
m =6

c= 20-m
c= 20-6
c= 14

Montamos o par (c,m)

(14,6)