9C

Equations with fractions

Solving linear equations that contain fractions by multiplying both sides by the denominator.

Clear the fraction

Example 1●

Solve $\dfrac{x}{4} + 3 = 8$.

$\dfrac{x}{4} = 5$
Subtract 3.
$x = 20$
Multiply by 4.
Example 2●●

Solve $\dfrac{2a + 1}{3} = 5$.

$2a + 1 = 15$
Multiply by 3 (the whole top is divided by 3).
$2a = 14$, so $a = 7$.
Example 3●●

Solve $\dfrac{3m}{5} = 6$.

$3m = 30$
$m = 10$
Flashcards
Undo $div 5$
Multiply both sides by 5.
Solve $dfrac{x}{2} = 9$
$x = 18$
Solve $dfrac{x + 1}{2} = 4$
$x = 7$
Practice
  1. Solve $\dfrac{x}{4} + 3 = 8$.

  2. Solve $\dfrac{2a + 1}{3} = 5$.

  3. Solve $\dfrac{3m}{5} = 6$.

  4. Solve $\dfrac{x}{2} = 9$.

  5. Solve $\dfrac{x + 1}{2} = 4$.

  6. Solve $\dfrac{y}{3} = -4$.

  7. Solve $\dfrac{k}{7} - 1 = 1$.

  8. Solve $\dfrac{n - 5}{2} = 3$.

More questions

New numbers every time. Keep going until you get five in a row.

Formula sheet