Question

please tell ans fast

Answer 1

here is the proof of how 9^n can have unit digit only 1 or 9 and not any other

Answer 2

${9}^{x}$
Put x=1 we get 9
Put x=2 we get 81
Put x=3 we get 729

So the concept we have here is that whatever is the power of 9 we will get either 1 or 9 as a unit digit

When power is odd we get 9 as the last digit and when power is ever we get 1 as the last digit