Get the most out of your questions with the extensive resources available on IDNLearn.com. Ask your questions and receive reliable, detailed answers from our dedicated community of experts.

What is the ones digit when you do 9 to the power of 999?

Sagot :

Answer:

1

Step-by-step explanation:

I used a calculator.

correct me if I'm wrong

Answer:

9

Step-by-step explanation:

9 is congruent to -1 mod 10

(-1)^999 = -1, because 999 is odd, and when you raise -1 to an odd power you get -1

so the last digit is congruent to -1 mod 10

hence the last digit is 9