Question

Dau 100 puncte !!!!!!​

Answer 1

Răspuns:

Explicație pas cu pas:

Salutare!      

a)

$\bf n = 10^{2018} +10^{2017} -1$

$\bf n = 10^{2018} +10^{2017} -1$

$\bf n=1\underset{\it 2018~de~zerouri}{\underbrace{000..........000}}+1\underset{\it 2017~de~zerouri}{\underbrace{000..........000}}-1$

$\bf n=11\underset{\it 2017~de~zerouri}{\underbrace{000..........000}}-1$

$\bf n=11\underset{\it 2017~de~9}{\underbrace{99.........99}}$

$\bf Numarul_{~cifrelor~lui~ n} = 2+2017 = 2019$

$\large\boxed{\boxed{\bf Numarul_{~cifrelor~lui~ n} = 2019~ cifre}}$

b)

$\bf Suma_{~cifrelor~lui~n}=1+1+\underset{\it 2017~de~9}{\underbrace{9+9+......+9+9}}$

$\bf Suma_{~cifrelor~lui~n}=2+2017 \cdot 9$

$\bf Suma_{~cifrelor~lui~n}=2+18153$

$\large\boxed{\boxed{\bf Suma_{~cifrelor~lui~n}=18155}}$

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