Răspuns:
[tex] {2}^{2005} + {2}^{2003} + {2}^{2001} = {2}^{2001} \times {2}^{4} + {2}^{2001} \times {2}^{2} + {2}^{2001} = {2}^{2001} \times ( {2}^{4} + {2}^{2} + 1) = {2}^{2001} \times (16 + 4 + 1) = {2}^{2001} \times 21[/tex]
Te folosesti de proprietatea puterilor : 2 la puterea a 3a = 2 la puterea (2+1)= 2 la puterea a2a * 2 la puterea 1
