(a) Subtract 4a - 7ab + 3b + 12 from 12a - 9ab + 5b - 3
(b) Subtract 3xy + 5yz - 7zx from 5xy - 2yz - 2zx +10xyz
(c) Subtract 4p²q - 3pq + 5pq² - 8p + 7q - 10 from 18 - 3p - 11q + 5 pq - 2pq² + 5p²q

Solution:

The given algebraic expressions are written by rearranging and combining like terms followed by performing the subtraction operation as follows:

(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 + 5pq + 3pq - 2pq²  – 5pq² + 5p²q – 4p²q

= 28 + 5p – 18q + 8pq – 7pq² + p²q

The difference of the given expressions are (i) 8a - 2ab + 2b - 15 (ii) 2xy - 7yz + 5zx + 10xyz (iii) 28 + 5p - 18q + 8pq - 7pq² + p²q

☛ Check: NCERT Solutions for Class 8 Maths Chapter 9

Video Solution:

(a) Subtract 4a - 7ab + 3b + 12 from 12a - 9ab + 5b - 3 (b) Subtract 3xy + 5yz - 7zx from 5xy - 2 yz - 2zx +10xyz (c) Subtract 4p²q - 3pq + 5pq² - 8p + 7q - 10 from 18 - 3p - 11q + 5 pq - 2 pq² + 5 p²q

Maths NCERT Solutions Class 8 Chapter 9 Exercise 9.1 Question 4

Summary:

The difference of the given expressions (a) 4a - 7ab + 3b + 12 from 12a - 9ab + 5b - 3, (b) 3xy + 5yz - 7zx from 5xy - 2 yz - 2zx +10xyz and (c) 4p²q - 3pq + 5pq² - 8p + 7q - 10 from 18 - 3p - 11q + 5 pq - 2 pq² + 5 p²q are (i) 8a - 2ab + 2b - 15 (ii) 2xy - 7yz + 5zx + 10xyz (iii) 28 + 5p - 18q + 8pq - 7pq² + p²q

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