Multiplying Out Brackets.

1
Multiplying Out Brackets.

• Double Brackets.

2
What Do Double Brackets Represent?
A2
2x
A1
Consider the area of this rectangle.
A4
A3
3
A1
2x2
A2
12x
x
6
A3
3x
Total Area 2x2 12x 3x 18
A4
18
2x2 15x 18
Final Answer
3
How To Multiply Out A Double Bracket.
Consider
Golden Rule Everything in the first bracket
multiplies the second bracket.
( 2x 3 ) ( x 6)
2x
(x 6 )
3
( X 6)
2x2
12x
3x
18
2x2
15x
18
The same as the area of the rectangle.
4
What Goes In The Box?
(4x 3 ) ( 5x 6)
( 5x 6)
( 5x 6)
3
4x
24x
15x
18
20x2
20x2
39x
18
5
Dealing With Negatives Positives.
When you multiply. If the signs are the same you
get a plus if they are different you get a
negative.
You should know that
x

x -
-
Now try these
- x
-
(1) 4 x 3
(6) 4 3
-12
1
7
(2) 2 x 5
(7) 4 3
10
- x -

-14
-12
(3) - 7 x 2
(8) 5 7
(4) 6 x 8
(9) 6 3
48
3
(5) 6 x 9
(10) 5 4
54
-1
6
Brackets With Negatives Positives.
Using the rules you have just seen complete the
following.
( 2x 7 ) ( 5x 4)
( 5x 4)
2x
( 5x 4)
-7
10x2
8x
35x
28
-
-

x
-

10x2
28
43
7
What Goes In The Box?
((3x 4 ) ( 6x 7)
3x
( 6x 7 )
- 4
( 6x 7 )
18x2
28
- 21x
- 24x
18x2
-45x
28
8
What Goes In The Box?
( 2x 4 ) ( 3x 8 )
( 3x - 8 )
( 3x - 8 )
2x
4
-16x
12x
6x2
-32
6x2
-4x
-32