Introduction to Algebra

Success Criteria

At the end of this chapter, students are able to:

  1. Substitute values into an algebraic expression.

  2. Identify like and unlike terms.

  3. Simplify an algebraic expression by adding and subtracting like terms.

  4. Expand an algebraic expression.

  5. Factorise an algebraic expression.

  6. Solve an algebraic equation.

  7. Solve a simple linear inequality.

What is Algebra?

The word Algebra comes from the Arabic word الجبر (al-jabr) which means "restoration". I find the Chinese word for Algebra, 代数 , much more intuitive because it simply means "the representation of numbers" (代表数字).

Through this chapter, we will get to understand how alphabets and other symbols can be used to represent unknown numbers and we will learn how to simplify and solve these algebraic problems and "restore" the right numbers to these symbols.

An Example

Recall in Primary school, you would have come across a problem like this:

The box is used to represented an unknown number for students to fill in. In Algebra, we use a letter (like the letter x) to formally represent the unknown number.

Try it!

Fill in the blank below with the correct value.

Try it again! (But with Algebra)

Lets do it again but this time instead of filling in a box, we use the letter x to represent the unknown value. Can you find the value of x?

Next: Lets now examine the Notations in Algebra