n1+6 = n6, n1=n6-6
n2-6 = n6, n2=n6+6
n3/6 = n6, n3=6n6
6n4 = n6, n4=n6 / 6
n5-12 = n6, n5=n6+12
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n1+n2+n3+n4+n5+n6 =
n6-6 + n6+6 + 6n6 + n6 / 6 + n6+12 + n6 = 177
n6 (10+1/6) = 177-12
61n6 / 6 = 165
61n6 = 6*165
61n6 = 990
n6= 990/61 =16,229...∉ N, deci problema este incompatibila(nu are solutie in N)