Here’s a great YouTube Video that introduces you to algebra.
Algebra is a lot like arithmetic. It uses the same rules of arithmetic and also the same four main operations: addition, subtraction, multiplication and division.
However, algebra introduces an additional element: the element of the unknown. The objective of many algebraic equation is to figure out the unknown or to come as close to it as possible.
In algebra, the unknown number is represented by a letter. You can use any letter of the English or Greek alphabet to represent an unknown number in algebraic equation, however, the most commonly used letter is x.
For example, you can write an algebraic equation such as:
x + 1 = 3
In the above algebraic equation, the letter x represents an unknown number. However, it is easy to figure out that that unknown number is 2.
2 + 1 = 3
The algebraic expression x + 1 = 3 can be stated in words as follows:
An unknown number “x” added to the number “1” is equal to the number 3.
It is common knowledge that we need to add the number 2 to the number 1 to get the number 3. Therefore, we know that x = 2.
However, the correct way to go about solving such an algebraic equation is to first group like terms together. That is we move all the numbers to one side, and leave the letters or symbols on the other side.
Therefore, x + 1 = 3 is simplified by changing it to x = 3 – 1. So why is x + 1 = 3 the same as x = 3 – 1? That’s because, when we move numbers from one side of the equal sign to the other, the number transitioned changes from negative to positive or positive to negative. For example, when the 1 was on the left of the equal sign it was a positive 1; when we move it to the right of the equal sign it becomes a negative 1. That’s just the rule. So by moving “like terms together” we are able to simplify or solve the algebraic equation.
The algebraic equation x + 1 = 3 is an example of a simultaneous equation because both sides of equal sign has the same value. The word “simultaneous” comes from the root word “same.” On the left we have 2 + 1, and on the right of the equal sign we have the number 3. Therefore, the values on the right and left of the equal sign are the same or “simultaneous.”
The algebraic equation x + 1 = 3 is an example of a very simple algebraic equation. Usually, in algebra, things get a lot more complicated and fun, as you’ll learn in future lessons.