Answer: AFC won 18 times, NFC won 20 times
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N = number of times an NFC team won the superbowl
A = number of times an AFC team won the superbowl
The two unknown numbers (N and A) must add to 38 as there are no other options (either there is an NFC or AFC champion) so N+A = 38
The other equation is N = A+2 because "the NCF won two more games than the AFC"
We can replace the "N" in N+A = 38 with A+2 because N = A+2, meaning that N and A+2 are the same
So,
N+A = 38
A+2+A = 38 ... replace N with A+2; solve for A
2A+2 = 38
2A+2-2 = 38-2
2A = 36
2A/2 = 36/2
A = 18
The AFC won 18 times. Use this value of A to find N
N = A+2
N = 18+2
N = 20
The NFC won 20 times.
As a check, adding up the two counts should get us 38
N+A = 38
20+18 = 38
38 = 38
Answer is confirmed