Linear equations are the foundation of all algebra. They are used to solve everyday problems like calculating discounts, finding unknown costs, and programming software logic.
An equation is like a balanced scale. As long as you do the exact same thing to both sides (add, subtract, multiply, or divide), the scale stays balanced. We use this property to reveal the unknown 'x'.
A common mistake is forgetting to change the sign when moving a term to the other side (transposition). Moving '+3' to the other side becomes '-3' because you are actually subtracting 3 from both sides.
Let's try solving these basic linear equations!
The word 'equation' comes from the Latin 'aequare', meaning 'to make equal'. The equal sign (=) was invented by Robert Recorde in 1557 because he was tired of writing 'is equal to' repeatedly. He chose two parallel lines because 'noe.2. thynges, can be moare equalle'.