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Algebraic Equation — Definition, Formula & Examples

An algebraic equation is a mathematical statement that uses an equals sign to show two expressions are equal, where at least one expression contains a variable (like xx or yy).

An algebraic equation is a statement of equality between two algebraic expressions, containing one or more variables and constants connected by arithmetic operations, for which specific values of the variables make the statement true.

How It Works

To work with an algebraic equation, your goal is usually to find the value of the unknown variable that makes both sides equal. You do this by performing the same operation on both sides — adding, subtracting, multiplying, or dividing — until the variable is isolated. The value you find is called the solution of the equation.

Worked Example

Problem: Solve the algebraic equation 2x+5=132x + 5 = 13.
Step 1: Subtract 5 from both sides to begin isolating xx.
2x+55=135    2x=82x + 5 - 5 = 13 - 5 \implies 2x = 8
Step 2: Divide both sides by 2.
2x2=82    x=4\frac{2x}{2} = \frac{8}{2} \implies x = 4
Step 3: Check by substituting x=4x = 4 back into the original equation.
2(4)+5=8+5=132(4) + 5 = 8 + 5 = 13 \checkmark
Answer: x=4x = 4

Why It Matters

Algebraic equations are the foundation of every algebra course and appear constantly in science, engineering, and finance. Whenever you need to find an unknown quantity — the time for a trip, the cost of an item, or the speed of an object — you set up and solve an algebraic equation.

Common Mistakes

Mistake: Confusing an algebraic expression (like 3x+73x + 7) with an algebraic equation.
Correction: An equation must have an equals sign. The expression 3x+73x + 7 is not an equation, but 3x+7=223x + 7 = 22 is.