Equations

5 minQuiz at the end

What is an Equation?

An equation is a mathematical statement showing that two expressions are equal, connected by an = sign.

3x + 5 = 11 is an equation. 3x + 5 is an expression.

The Golden Rule

Whatever you do to one side, you must do to the other. Think of an equation as a balanced scale.

Solving One-Step Equations

Addition/Subtraction:

  • x + 7 = 15 β†’ subtract 7 from both sides β†’ x = 8

Multiplication/Division:

  • 3x = 18 β†’ divide both sides by 3 β†’ x = 6

Solving Two-Step Equations

Work in reverse order of operations (undo addition/subtraction first, then multiplication/division):

2x + 5 = 13 β†’ subtract 5: 2x = 8 β†’ divide by 2: x = 4

Equations with Fractions

x/4 - 3 = 2 β†’ add 3: x/4 = 5 β†’ multiply by 4: x = 20

Checking Your Answer

Substitute your answer back into the original equation:

  • 2(4) + 5 = 8 + 5 = 13 βœ“