5C

Expanding brackets

Expanding expressions with the distributive law, including negative and pronumeral factors, and expanding then simplifying.

The distributive law

Distributive law
$$a(b + c) = ab + ac \qquad a(b - c) = ab - ac$$
Example 1●

Expand $-2x(3x - 5)$.

$-2x \times 3x = -6x^2$ and $-2x \times (-5) = 10x$.
$= -6x^2 + 10x$
Example 2●●

Expand and simplify $4(2a + 1) - 3(a - 2)$.

$8a + 4 - 3a + 6$
$= 5a + 10$
Flashcards
$-(x - 4)$
$-x + 4$
$3a(a + 2)$
$3a^2 + 6a$
$-2(5 - y)$
$-10 + 2y$
Practice
  1. Expand $-2x(3x - 5)$.

  2. Expand and simplify $4(2a + 1) - 3(a - 2)$.

  3. Expand $-(x - 4)$.

  4. Expand $3a(a + 2)$.

  5. Expand $-2(5 - y)$.

  6. Expand and simplify $2(x + 4) + 5x - 6$.

  7. Expand and simplify $x(x + 3) + 4x$.

  8. Expand and simplify $3(m + 2) - 5(m - 2)$.

More questions

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

Formula sheet