Let r and b represent the number of red and brown m%ms respectively.
r=b+1 and
r+b=13, using r found above we have:
b+1+b=13 combine like terms (b+b=2b)
2b+1=13 subtract 1 from both sides
2b=12 divide both sides by 2
b=6, and since r=13-a
r=7
So there are 6 brown and 7 red m&ms
