Expanding Brackets

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ALGEBRA:

ALGEBRA

Expanding Brackets:

Expanding Brackets

- Distributive Rule:

- Distributive Rule

One Bracket:

A ( B + C ) = A B + A C One Bracket

Similarly:

Similarly A ( B - C ) = A B - A C

Applying Rule To One Bracket:

Applying Rule To One Bracket 4a (3a + 5) = 4a x 3a + 4a x 5 = 4 x a x 3 x a + 4 x a x 5 = 4 x 3 x a x a + 4 x 5 x a = 12 a 2 + 20 a

Note 1: only like terms can be added :

Note 1: only like terms can be added Note 2: When multiplying terms, 1 st : x signs 2 nd : x numbers 3 rd : x letters (symbols)

Expanding Two Brackets:

Expanding Two Brackets 1. (a + b)(c + d) = ac + ad + bc + bd

Slide 9:

2. (a - b)(c - d) = ac - ad - bc + bd

Take A Break:

Take A Break

Expanding Two Brackets::

Expanding Two Brackets: Eg. ( a + 5 )(a - 6)

Expanding Two Brackets::

Expanding Two Brackets: ( a + 5 )(a - 6) = a x a + a x (-6) + 5 x a + 5 x (-6)

OR:

OR ( a + 5 )(a - 6) = a x a + 5 x a + a x (-6) + 5 x (-6)

:

= a 2 + ( - 6a ) + 5a + ( - 30 ) = a 2 – 6a + 5a – 30

And, a2 – 6a + 5a – 30 = a2 – a – 30:

And, a 2 – 6a + 5a – 30 = a 2 – a – 30