Question

Tim so tan chung cua so sau:

a.2 2009

b.3 2010

c.9 999

Giup minh nhanh voi 

Answer 1

a) 2²⁰⁰⁹=2^4.502+1=(2⁴)⁵⁰².2=16⁵⁰².2=...6 .2=...2

b)3²⁰¹⁰=3^4.502+2=(3⁴)⁵⁰².9=...1.9=...9

c)9⁹⁹⁹=9^2.499+1=9^2.499.9=...1.9=...9

Answer 2

a ) 2²⁰⁰⁹ = 2^4.502+1 = 2^4.502 . 2 = ( 2⁴ ) ⁵⁰² . 2 = 16⁵⁰² . 2 = ...6 . 2 = ...2

b ) 3²⁰¹⁰ = 3^4.502+2 = 3^4.502 . 3² = ( 3⁴ ) ⁵⁰² . 9 = 81⁵⁰² . 9 = ...1 . 9 = ...9

c ) 9⁹⁹⁹ = 9^2.499+1 = 9^2.499 . 9 = ( 9² ) ⁴⁹⁹ . 9 = 81⁴⁹⁹ . 9 = ...1 . 9 = ...9