Jawab:

Solution:

(i) 21b – 32 + lb – 20b

Combining the like terms, we have

= (21b + 7b – 20b) + (-32)

= (21 + 7 – 20)b + (-32)

= (8)b + (-32) = 8b – 32

(ii) -z² + 13z² – 5z + 7z3 – 15z

Collecting the like terms, we have:

= (7z3) + (- z² + 13z²) + (- 5z – 15z)

= (7z3) + (-1 + 13)z² + (- 5 – 15)z

= (7)z3 + (12)z² + (- 20)z

= 7z3 + 12z² – 20z

(iii) p – (p – q) – q – (q – p)

We have: p – (p – q) – q – (q – p)

=p – p + q – q – q + p

Collecting the like terms, we have:

(p – p + p) + (q – q – q)

= (1 – 1 + 1)p + (1 – 1 – 1 )q

= (1)p + (- 1 )q

= p – q

(iv) 3a – 2b – ab – (a – b + ab) + 3ab + b – a

We have:

3a – 2b – ab – (a – b + ab) + 3ab + b – a

= 3a – 2b – ab – a + b – ab + 3ab + b – a

Collecting the like terms, we have:

(3a – a – a) + (-2b + b + b) + (- ab – ab + 3ab)

= (3 – 1 – 1)a + (- 2 + 1 + 1)b + (- 1 – 1 + 3)ab

= (1)a + (0)b + (+1)ab = a + ab

(v) 5x²y – 5x² + 3yx² – 3y² + x² – y² + 8xy² – 3y

Collecting the like terms, we have:

(5x²y + 3yx²) + (8xy²) + (- 5x² + x²) + (- 3y² – y² – 3y² )

= (5 + 3 )x² y + (8 )xy² + (- 5 + 1)x² + (- 3 1 – 3)y²

= 8x²y + 8xy² + (- 4)x² + (- 7)y²

= 8x²y + 8xy² – 4x² – 7y²

(vi) (3y² + 5y – 4) – (8y – y² – 4)

We have:

(3y² + 5y – 4) – (8y – y² – 4) = 3y² + 5y – 4 – 8y + y² + 4

Collecting the like terms, we have:

(3y² + y²) + (5y – 8y) + (- 4 + 4)

= (3 + 1)y² + (5 – 8)y + (- 4 + 4)

= (4)y² + (- 3 )y + (0)

= 4y² – 3y