Definition of expansion in maths

meaning to multiply something into a term x. for example, this term x can be (3+a), or even (a+b+c+8). let us name that something 'y'. to expand, we put y(x), meaning y times x. another example, -g(a) = -ag, or minus (a times g). if the set x contains more than one term, multiply all the terms by y. y(a+b) = ay + by.remember, minus times minus is a plus, and minus times plus is minus.