Question

va rog ajutati-ma! a=2 la puterea 1990- 2 la puterea 1989- 2 la puterea 1988

Answer 1

$a= 2^{1988}(2^2-2^1-1)= 2^{1988}(4-2-1)= 2^{1998}*1= 2^{1988}$