Question

ma puteti ajuta? VA ROG O REZOLVARE CEL PUTIN PENTRU EXERCITIUL 34 CAT MAI CLARA

Answer 1

Răspuns:

34

a)2×(3+3^2+3^3+...+3^2000)=4×9^998×X-3^2000-3

S=3+3^2+3^3+...+3^2000 |X3

3S=3^2+3^3+3^4+...+3^2000+3-3

3S=S+3^2001-3

3S-S=3^2001-3

=>S=(3^2001-3):2

Avem:

2×(3^2001-3):2=4×(3^2)^998×X-3^200-3

3^2001=4×3^1996×X-3^2000-3

3^2001=4×3^1996×X-3^200

3^2001=3^1996(4×X-3^4) |:3^1996

3^5=4X-3^4

4X=3^5+3^4

4X=3^4(3+1)

4X=4×3^4

X=3^4

X=81

Scuze, dar nu le pot rezolva pe toate....