What are the positive residual obtained when (17 ^ 15 +8 ^ 25) ^ 10 divided by 10?
should be 1
do you want an explanation?
Yes please
ok :) so, to start off, we need to understand that the positive residual is like a remainder...so anything that is a remainder after being divided by 10 is just the number that is in the one's digit....
like....225 divided by 10...the residue would be 5. 332 divided by 10, the residual would be 2. Do you get that??
Maribor?
can you show me how you resolved the issue
I will, but I need to make sure you got what I said above XD
yes I do
ok, good :) so that means you only need to concentrate on the last digit of every number. 17^1=17 last digit is 7 17^2=289 last digit is 9 17^3=4913 last digit is 3 17^4=83521 last digit is 1 17^5=1419857 last digit is 7 So, by this, we can see that this sequence of 7931 is going to loop every four exponents. In the question above, 17 is raised to the 15 th power. Therefore, 7 9 3 1 7 9 3 1 7 9 3 1 7 9 3 The 15th number ends with 3.
OK Thanks for your help
Now, taking the same pattern with 8: 8 4 2 6 8 4 2 6 8 4 2 6 8 4 2 6 8 4 2 6 8 4 2 6 8. The last number raised to the 25th power is 8.
add these last digits up and you should get 1. 1^10 is 1 so the remainder of this equation is 1. Sorry for the lengthy explanation XD
Thanks again
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