Verify that -(-x)=x for. (i) (ii)

NCERT - Mathematics

Book: NCERT - Mathematics

Chapter: 1. Rational Numbers

Subject: Maths - Class 8^th

Q. No. 3 of Exercises 1.1

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3

Verify that -(-x)=x for.

(i) $x=\frac{11}{15}$

(ii) $x=\frac{-13}{17}$

(i) Here $x=\frac{11}{15}$

The additive inverse of “a” is given as “-a”

∴ Additive Inverse of $\frac{11}{15}$ will be $\frac{-11}{15}$

$\therefore -(-x)= -\frac{-11}{15}= \frac{11}{15}=x$

(ii) Here

The additive inverse of “a” is given as “-a”

Therefore,

∴ Additive Inverse of $-\frac{13}{17}$ will be $\frac{13}{17}$

$\therefore -(-x)= -\frac{13}{17}=x$

4

Chapter Exercises

Exercises 1.1

Exercises 1.2

1

Using appropriate properties find.
(i)
(ii)

2

Write the additive inverse of each of the following.
(i)

(ii)

(iii)

(iv)

(v)

3

Verify that -(-x)=x for.

(i) $x=\frac{11}{15}$

(ii) $x=\frac{-13}{17}$

4

Find the multiplicative inverse of the following.
(i) -13

(ii)

(iii)

(iv)

(v)

(vi) -1

5

Name the property under multiplication used in each of the following.
(i)

(ii)

(iii)

6

Multiply by the reciprocal of

7

Tell what property allows you to compute as

8

Is the multiplicative inverse of Why or why not?

9

Is 0.3 the multiplicative inverse of Why or why not?

10

Write.
(i) The rational number that does not have a reciprocal.

(ii) The rational numbers that are equal to their reciprocals.

(iii) The rational number that is equal to its negative.

11

Fill in the blanks.
(i) Zero has ____ reciprocal.

(ii) The numbers and are their own reciprocals.

(iii) The reciprocal of – 5 is .

(iv) Reciprocal of where is .

(v) The product of two rational numbers is always a _.

(vi) The reciprocal of a positive rational number is ______.