Solving linear equations

Use inverse operations to get the unknown on its own, keep the equation balanced, and always check your answer.

1 мин чтенияОбновлено 18 октября 2026 г.Автор: Sumzo teamПроверил(а): Sumzo team

An equation says two expressions are equal. A linear equation has the unknown only to the first power, like $3x + 5 = 20$ . To solve it, undo what has been done to $x$ , doing the same thing to both sides so the equation stays balanced.

Разобранный пример

A two-step equation

Solve $3x + 5 = 20$ .

Показать решение

Subtract 5 from both sides. $3x = 15$
Divide both sides by 3. $x = 5$
Check by substituting. $3(5) + 5 = 20 \checkmark$

Ответ: $x = 5$

Проверено математическим движком Sumzo

Brackets and unknowns on both sides

Expand any brackets.
Collect the $x$ terms on one side and the numbers on the other.
Divide by the coefficient of $x$ .

Разобранный пример

Brackets and x on both sides

Solve $3(x - 2) = x + 4$ .

Показать решение

Expand the bracket. $3x - 6 = x + 4$
Subtract $x$ from both sides and add 6. $2x = 10$
Divide by 2. $x = 5$

Ответ: $x = 5$

Проверено математическим движком Sumzo

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