Let x be a positive integer, what is the remainder when 5^(3x+1)+5 is divided by 5?
Answers:
A) 0
B) 1
C) 2
D) 3
E) 4
For: (5^(3x+1)+5)/3   Let n = 3x + 1   5^n   5^1 = 5   5^2 = 25   5^3 = 125, ... last digit is always 5.   Rule: x^(m+n) = (x^m)(x^n)   (5^(3x))(5^1)   Rule: x^(mn) = (x^m)^n   ((5^3)^x)(5) =&gt; Now, (5)(125^x) + 5 = (5)(5) + 5 =&gt; Finally, 30/5 divides evenly with 0 remainder.   0nswer: 0
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Let x be a positive integer, what is the remainder when 5^(3x+1)+5 is divided by 5?