During addition and multiplication,
you can switch positions without
affecting the answer.
a + b = b + a
ab = ba
During subtraction
and division, if you switch positions, the answer will change.
a – b ¹ b – a
a ¸ b ¹ b ¸ a
To expand, multiply each and every term inside the brackets.
4(3x – 5)
= 4 (3x) +
4 (– 5)
= 12x – 20
(2x) (3x – 5)
= (2x) (3x) + (2x) (– 5)
= 6x2 – 10x
(2x + 3y) (3x – 5)
= (2x) (3x – 5) + (3y) (3x – 5)
= (2x) (3x) + (2x) (– 5)
+ (3y) (3x) + (3y) (– 5)
+ (3y) (3x) + (3y) (– 5)
= 6x2 – 10x +
9xy – 15y
To factorise,
take
out common terms.
2a2b2 + 10a2b +
20b
2 and b are common in all these
terms.
2a2b2 + 10a2b + 20b = 2b (a2b + 5a2 + 10)
Factorise:
2ax + 3ay + 2bx + 3by
First two terms: a is common
Last
two terms: b is common.
= a (2x + 3y) + b (2x + 3y)
Now (2x + 3y) is common
= (2x + 3y) (a + b)
