Variables Math Example 1

Follow the full solution, then compare it with the other examples linked below.

Example 1

easy
If x+5=12x + 5 = 12, what value does xx represent?

Solution

  1. 1
    The variable xx is a placeholder for an unknown number.
  2. 2
    Subtract 5 from both sides: x=12−5=7x = 12 - 5 = 7.
  3. 3
    Check: 7+5=127 + 5 = 12 ✓

Answer

x=7x = 7
A variable is a symbol that stands for an unknown value. To find its value, we perform operations that isolate it on one side of the equation.

About Variables

A symbol (usually a letter like xx) that represents an unknown or changing quantity in a mathematical expression.

Learn more about Variables →

More Variables Examples

Example 2 medium

Evaluate the expression [formula] when [formula] and [formula].

Example 3 easy

If [formula], what is the value of [formula]?

Example 4 medium

Write an expression using a variable for: 'a number increased by 8.'

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