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Linear equations

Isolate the unknown by doing the same thing to both sides.

A linear equation has the unknown to the first power only. Solving it is a sequence of legal moves — add, subtract, multiply or divide both sides by the same thing — chosen to leave the unknown alone. The graph shows the line y = 2x + 3 − 7; the solution is where it crosses the axis.

Worked example: 2x + 3 = 7

Algebra · Linear-Equations

Solve 2x + 3 = 7

2 x + 3 = 7

Step by step

  1. 2 x + 3 = 7

    Start from the equation as given.

  2. 2 x - 4 = 0

    Bring everything to one side and collect like terms so the right-hand side is 0.

  3. 2 x = 4

    Move the constant term to the other side: subtract -4 from both sides.

  4. x = \frac{4}{2}

    Divide both sides by 2, the coefficient of x.

  5. x = 2

    Simplify the fraction.

Reveal the answer
x = 2

Try your own

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