Simplify each of the following:

(i)

(ii)

(iii)

(iv)

(v)

(i)

= x² - 3x² – 3x + 5x + 5 - 7

= (2x² – 3x²) - (6x + 5x) +

= x² - +

= x² - x +

(ii)

= 5 – 3x + 2y – 2x + y – 3x + 7y – 9

= - 8x + 10y – 4

(iii)

= x²y + x²y - xy² - xy² + xy + xy

= (165x²y + 2x²y) + (-126xy² – 4xy²) +

= x²y - xy² + xy

= x²y - xy² + xy

(iv)

= y² – 2y² - y² - y - y - y + 11 + 3 – 2

= (y² – 6y² + 2y²) - (4y – y – 2y) + 14 – 2

= y² - y + 12

= -y² – y + 12

(v)

= a²b²c - a²b²c + ab²c + ab²c - abc² - abc² + a²bc

= a²b²c + ab²c - abc² + a²bc