Question

A=2 la puterea 1990-2 la puterea 1989-2 la puterea 1988

Answer 1

A= 2 ^1990 - 2^1
A= 2^1989

Answer 2

${2}^{1990} - {2}^{1989} - {2}^{1988} = {2}^{1990} - {2}^{1} = {2}^{1989}$
Succes!!!!..........