Simplify each of the following:
(i) 
(ii) 
(iii)
(iv)
(v) 
(i) 
= x2 - 
3x2 – 3x + 
5x + 5 - 
7
= 
(2x2 – 3x2) - 
(6x + 5x) + 
= 
x2 - 
+ 
= 
x2 - 
x + 
= 5 – 3x + 2y – 2x + y – 3x + 7y – 9
= - 8x + 10y – 4
= 
x2y + 
x2y - 
xy2 - 
xy2 + 
xy + 
xy
= 
(165x2y + 2x2y) + 
(-126xy2 – 4xy2) + 
= 
x2y - 
xy2 + 
xy
= 
x2y - 
xy2 + 
xy
= 
y2 – 2y2 - 
y2 - 
y - 
y - 
y + 11 + 3 – 2
= 
(y2 – 6y2 + 2y2) - 
(4y – y – 2y) + 14 – 2
= 
y2 - 
y + 12
= -y2 – y + 12
= 
a2b2c - 
a2b2c + 
ab2c + 
ab2c - 
abc2 - 
abc2 + 
a2bc
= 
a2b2c + 
ab2c - 
abc2 + 
a2bc
7