Explicație pas cu pas:
Trecem la b) , explicatii pas cu pas...
[tex]3^{80}-2*3^{79}-2*3^{78} =\\ =3^{78} *(3^{2}-2*3^{1} -2*3^{0} )=\\=3^{78}*(9-6-2)=\\=3^{78}[/tex]
Trecem la d) , explicatii pas cu pas...
[tex]2^{3n+1} +4^{n+1} *2^{n+2} -8^{n+1} =\\=2^{3n+1} +2^{2n+2} *2^{n+2}-2^{3n+3} =\\=2^{3n+1}+2^{3n+4} -2^{3n+3} =\\=2^{3n+1}*(2^{0}+ 2^{3} -2^{2} )=\\=2^{3n+1}*(1+8-4)=\\=2^{3n+1}*5[/tex]
Trecem la f) , explicatii pas cu pas...
[tex]9*25^{n} -5^{2n} =\\9*5^{2n}-5^{2n}=\\5^{2n}*(9-1)=\\5^{2n}*8[/tex]
Bafta!
