Match the expressions of column I with that of column II:
Column I Column II
(1) (21x + 13y)² (a) 441x² - 169y²
(2) (21x - 13y)² (b) 441x² + 169y² + 546xy
(3) (21x - 13y) (21x + 13y) (c) 441x² + 169y² - 546xy
(d) 441x² - 169y² + 546xy

Solution:

The Correct answer is (a).

Themultiplicative inverse of a number is defined as a number which when multiplied by the original number gives the product as 1. The multiplicative inverse of 'a' is denoted by a-1 or 1/a. The multiplicative inverse property says that the product of a number and its multiplicative inverse is 1.

Here, multiplicative inverse of 27 = 1/27 = 2-7.

✦ Try This: What is the multiplicative inverse of 1/7?

Solution: Given term is 1/7.

Multiplicative inverse of 1/7 = (1/7)-1 = 7

Or when we multiply 1/7 × 7 = 1

∴ multiplicative inverse of 1/7 is 7.

☛ Also Check: NCERT Solutions for Class 8 Maths Chapter 12

NCERT Exemplar Class 8 Maths Chapter 8 Sample Problem 1

Multiplicative inverse of 2⁷ is (a) 2-7, (b) 72, (c) -27, (d) -27

Summary:

Multiplicative inverse of 27 is 2-7

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