When we divide the numbers 272 758 and 273 437 by a two-digit number N, we get remainders of 13 and 17 respectively. Find the sum of the
digits of N.
(A) 6
(B) 9
(C) 10
(D) 11
(E) 12
answer is attached but I don't understand it...

Solve the system. -a+4b+2c=-8 3a+b-4c=9 b=-1 a.(0,11) ,-1,2) c.(1,1,-2) d.(2,-1,-1)

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