Which of the following is not equal to 1
a. (23× 32)/(4 × 18)
b. [(-2)3× (-2)4] ÷ (-2)7
c. (30× 53)/(5 × 25)
d. 24/ (70+ 30)3

Solution:

Consider all the options

1. (23× 32)/(4 × 18)

= (2 × 2 × 2 × 3 × 3)/ (4 × 18)

= (8 × 9)/ (4 × 18)

= 1

2. [(-2)3× (-2)4]÷(-2)7

Using am × an = am+n

= (-2)3 + 4/ (-2)7

Using am/an = am-n

= (-2)7/ (-2)7

= 1

3. (30× 53)/(5 × 25)

= (1 × 5 × 5 × 5)/ (5 × 25)

= (5 × 25)/ (5 × 25)

= 1

4. 24/ (70+ 30)3

= 24/ 23

= 24-3

= 21

= 2

Therefore, option d is not equal to 1.

✦ Try This: Cube of (-1/7) is

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 13

NCERT Exemplar Class 7 Maths Chapter 11 Problem 15

Which of the following is not equal to 1: a. (23 × 32)/(4 × 18), b. [(-2)3 × (-2)4] ÷ (-2)7, c. (30 × 53)/(5 × 25), d. 24/ (70 + 30)3

Summary:

Therefore, option (d) 24/ (70 + 30)3 is not equal to 1

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