Question -
Answer -
(a) (12a – 9ab + 5b – 3) – (4a – 7ab + 3b+ 12)
= 12a – 9ab + 5b – 3 – 4a + 7ab – 3b – 12
= 12a – 4a -9ab + 7ab +5b – 3b -3 -12
= 8a – 2ab + 2b – 15
b) (5xy– 2yz – 2zx + 10xyz) – (3xy + 5yz – 7zx)
= 5xy – 2yz – 2zx + 10xyz – 3xy – 5yz + 7zx
=5xy – 3xy – 2yz – 5yz – 2zx + 7zx + 10xyz
= 2xy – 7yz + 5zx + 10xyz
c) (18– 3p – 11q + 5pq – 2pq2 +5p2q) – (4p2q – 3pq + 5pq2 –8p + 7q – 10)
= 18 – 3p – 11q + 5pq – 2pq2 +5p2q – 4p2q + 3pq – 5pq2 +8p – 7q + 10
=18+10 -3p+8p -11q – 7q + 5 pq+ 3pq- 2pq^2 – 5pq^2 + 5 p^2 q –4p^2 q
= 28 + 5p – 18q + 8pq – 7pq2 + p2q