Question

Determinati suma cifrelor numerelor: a) 5^2011*16^503 ; b) 50^20*2^28 .
Va rog ajutati-ma.. .-.

Answer 1

5^2011 x 16^503 =
=5^2011 x (2^4)^503=
=5^2011 x 2^2012=
=5^2011 x 2^2011 x2=
=10^2011 x 2 =
=10......0 (2011 zerouri x2 = 20.....0 (2011 zerouri 
suma cifrelor este 2+0*2011=2

50^20 x 2^28=
=2^20 x 25^20 x 2^28=
=5^40 x 2^48=
=5^40 x 2^40 x 2^8=
=10^40 x 2^8=
=10.....0 (40 zerouri) x 256 = 
=2560.......0(40 zerouri)
suma cifrelor = 2+5+6+40*0=13