Take away:
(i) 
(ii) 
(iii) 
(iv) 
(v) 
(i) 
= 
x3 - 
x2 + 
x + 
– (
x2 - 
x3 + 
+ 
x)
= 
x3 + 
x3 - 
x2 - 
x2 + 
x - 
x + 
- 
= 
x3 - 
x2 - 
- 
= 
x3 - 
x2 - 
- 
= 
a3 – 
a2 – 
– (
a2 + 
a2 + 
– 
= 
a5 - 
a3 - 
a2 - 
a2 - 
- 
+ 
= 
(2a3 – 9a3) – 
(3a2 – 10a2) – 
+ 
= 
a3 - 
a2 - 
- 
= 
- 
- 
x2 – (
x3 + 
x2 + 
x + 
)
= 
x3 - 
x2 - 
x2 - 
- 
+ 
- 
= 
x3 - 
x2- 
+ 
= 
x3 - 
x2 - 
– 1
= 
- 
y2 – (
y3 + 
y2 + 
y + 
)
= 
y3 - 
y2 - 
y2 - 
+ 
- 
= 
y3 + 
(-5y2 – 7y2) - 
y + 
= 
y3 - 
y2 - 
y - 
= 
ab - 
ac - 
bc – (
ac - 
ab + 
)
= 
ab - 
ab - 
ac - 
ac - 
bc - 
bc
= 
- 
- 
= 
ab - 
ac - 
bc
3