(i) Algebraic Expression • Terms are FORMED by the product of variables and constants, e.g. –3xy, 2xyz, 5x2, etc. • Terms are added to form expressions, e.g. –2xy + 5x2. • Expressions that contain exactly one, two and three terms are called monomials, BINOMIALS and TRINOMIALS, respectively. • In general, any expression containing one or more terms with non- zero coefficients (and with variables having non-negative exponents) is called a polynomial. • Like terms are formed from the same variables and the powers of these variables are ALSO the same. But coefficients of like terms need not be the same. • There are number of situations like finding the area of rectangle, triangle, etc. in which we need to multiply algebraic expressions. • Multiplication of two algebraic expressions is again an algebraic expression. • A monomial multiplied by a monomial always gives a monomial. • While multiplying a polynomial by a monomial, we multiply EVERY term in the polynomial by the monomial using the distributive law a ( b + c) = ab + ac.