Can somebody give me a mathematical definition of zero?

An alien has just landed from the planet, iksnimak. he would like to leam how to add two fractions when thedenominators are the same. write a paragraph that explains to our alien friend, in your own words, the detailsabout how to add the fractions, how to change the result to a mixed number, and how to reduce the fractionpart. use this problem as your example: the two fractions are 5/8 & 7/8

The product of two negative rational numbers is always zero sometimes zero never zero

Aheated piece of metal cools according to the function c(x) = (.5)x ? 7, where x is measured in hours. a device is added that aids in cooling according to the function h(x) = ? x ? 2. what will be the temperature of the metal after two hours?