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# Find the multiplicative inverse of the following

(i) -13 (ii) -13/19 (iii) 1/5 (iv) -5/8 × -3/7 (v) -1 × -2/5

(vi) -1

**Solution:**

The reciprocal of a given rational number is known as its multiplicative inverse. The product of a rational number and its multiplicative inverse is 1.

(i) The Multiplicative inverse of -13 is -1/13

∵ -13 × (-1/13) = 1

(ii) The Multiplicative inverse of -13/19 is -19/13

∵ -13/19 × (-19/13) = 1

(iii) The Multiplicative inverse of 1/5 is 5

∵ 1/5 × 5 = 1

(iv) The Multiplicative inverse of -5/8 × -3/7 is 56/15

∵ -5/8 × (-3/7) = 15/56 and 15/56 × 56/15 = 1

(v) The Multiplicative inverse of -1 × -2/5 is 5/2

∵ -1 × (-2/5) = 2/5 and 2/5 × 5/2 = 1

(vi) The Multiplicative inverse of -1 is -1

∵ -1 × (-1) = 1

**☛ Check: **NCERT Solutions for Class 8 Maths Chapter 1

**Video Solution:**

## Find the multiplicative inverse of the following (i) -13 (ii) -13/19 (iii) 1/5 (iv) -5/8 × -3/7 (v) -1 × -2/5 (vi) -1

NCERT Solutions Class 8 Maths Chapter 1 Exercise 1.1 Question 4

**Summary:**

The multiplicative inverse of the following (i) -13, (ii) -13/19, (iii) 1/5, (iv) -5/8 × -3/7, (v) -1 × -2/5 ,(vi) -1 are -1/13, -19/13, 5, 56/15, 5/2, and -1

**☛ Related Questions:**

- Name the property under multiplication used in each of the following: (i) -4/5 × 1 = 1 × -4/5 = -4/5 (ii) -13/17 × -2/7 = -2/7 × -13/17 (iii) -19/29 × 29/-19 = 1
- Multiply 6/13 by the reciprocal of -7/16. The multiplicative inverse of a number is defined as a number which when multiplied by the original number gives the product an identity
- Tell what property allows you to compute 1/3 × (6 × 4/5) as (1/3 × 6) × 4/3? The Associative property tells us that we can add/multiply the numbers in an equation irrespective of the grouping of those numbers.
- Is 8/9 the multiplicative inverse of -1 (1/8)? Why or why not?

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