How do you simplify 5^25 - 5^3?

1 Answer
Oct 5, 2015

5^25-5^3 = 298023223876953125 - 125 = 298023223876953000

Explanation:

How do we find 5^25 = 298023223876953125 ?

The obvious way is to start with 1 and multiply it by 5, 25 times.

I prefer to start with 10^25 = 10000000000000000000000000 and divide it by 2, 25 times...

10000000000000000000000000
color(white)(0)5000000000000000000000000
color(white)(0)2500000000000000000000000
color(white)(0)1250000000000000000000000
color(white)(00)625000000000000000000000
color(white)(00)312500000000000000000000
color(white)(00)156250000000000000000000
color(white)(000)78125000000000000000000
color(white)(000)39062500000000000000000
color(white)(000)19531250000000000000000
color(white)(0000)9765625000000000000000
color(white)(0000)4882812500000000000000
color(white)(0000)2441406250000000000000
color(white)(0000)1220703125000000000000
color(white)(00000)610351562500000000000
color(white)(00000)305175781250000000000
color(white)(00000)152587890625000000000
color(white)(000000)76293945312500000000
color(white)(000000)38146972656250000000
color(white)(000000)19073486328125000000
color(white)(0000000)9536743164062500000
color(white)(0000000)4768371582031250000
color(white)(0000000)2384185791015625000
color(white)(0000000)1192092895507812500
color(white)(00000000)596046447753906250
color(white)(00000000)298023223876953125