What is the units digit of the expression 14^7−18^4?  Options:
A) 0 B) 3 C) 4 D) 6 E) 8
Units digit of 14^7−18^4:   Consider the following unit digits:   4^1: 4   4^2: 6   4^3: 4   4^4: 6   ⇒ unit digit of 4^7 is: 4   The unit digit of 14^7 will also be 4   Also:   8^1: 8   8^2: 4   8^3: 2   8^4: 6   ⇒ unit digit of 8^4 is: 6   The unit digit of 18^4 will also be 6   Finally, 4-6 (or 14-6) = 8   Answer: 8)
<result>E</result>
What is the units digit of the expression 14^7−18^4?