a) The integer that represents '100 feet above sea level' is +100. The opposite integer is -100. In this case zero means sea level, so:
above sea level the quantities are positive
below sea level the quantities are negative
b) The integer that represents '32°C below zero' is -32. The opposite integer is +32. In this case zero means 0°C which is the water melting temperature (temperature when water passes from solid to liquid), so:
above zero the quantities are positive
below zero the quantities are negative
c) The integer that represents 'a withdrawal of $25' is -25. The opposite integer is +25. In this case zero means no entrances and no withdrawals, so:
