Year 8: Solve linear equations

What is a linear equation?

A linear equation is an equation where the highest power of the variable (usually ‘x’) is 1. It always represents a straight line when you graph it. It looks like this: a*x + b = 0 , where ‘a’ and ‘b’ are numbers.

Steps to Solve Linear Equations

1. Isolate the term with ‘x’: Your goal is to get ‘x’ all by itself on one side of the equation. Use opposite operations to get rid of the numbers next to the ‘x’.
2. Addition and Subtraction: If a number is being added to the term with ‘x’, subtract that number from *both* sides of the equation. If a number is being subtracted, add it to both sides.
3. Multiplication and Division: If the ‘x’ is being multiplied by a number, divide both sides by that number. If the ‘x’ is being divided by a number, multiply both sides by that number.
4. Check your solution: Once you've solved for ‘x’, substitute your answer back into the original equation to make sure it’s true.

Example

Solve: 2x + 3 = 7

1. Subtract 3 from both sides: 2x = 4
2. Divide both sides by 2: x = 2