Algebra Is a system consisting of a set, together with operations that follow certain properties.

Classification of numbers:a) Natural numbers - the set of positive whole numbers.Ex. 1,2,3,, nb) Integers the set of positive and negative whole numbers.Ex: 0, 1, 2, -4, -7, c) Rational numbers are numbers which can be expressed as quotient of two integers.

Ex: - 2, 5, , 0.3, d) Irrational numbers are numbers which cannot be expressed as quotient of two integers.

Ex: e) Real numbers are the set of rational and irrational numbers.f) Complex number A complex number is a number consisting of a real part and an imaginary part. Complex numbers extend the idea of the one-dimensional number line to the two-dimensional complex plane by using the number line for the real part and adding a vertical axis to plot the imaginary part. A complex number is of the form a + bi.

where: a and b are real numbers and