There are 128 teams in a softball tournament. In each round, half of the teams are eliminated. Which function can be used to find the number of teams remaining in the tournament after x rounds?
y= 128 (2)*
y = 0.5 (128)*
♪=128（0.5）*
y = 128*
y= 128 (2)*
y = 0.5 (128)*
♪=128（0.5）*
y = 128*