A expression in maths is a collection of terms without an equality sign.
For answer see http://mathsduck.co.uk/
it is across, like the horizon.
Mean means Average of a particular distribution Mean means Average of a particular distribution
well in literacy terms it means the way its set out like in a book or something not sure if there is a maths terms one though im not good at maths and I aint kidding
Interpret means to explain something like to explain remainders