Question

EXERCISE 5.2
1. Find the square of the following numbers.
(i) 32
(ii) 35
(v) 71
(vi) 46
(iii) 86
(iv) 93​

Answer 1

Answer:

Square of the following numbers:

(i) 32 = 1024

(ii) 35 = 1225

(iii) 86 = 7396

(iv) 93 = 8649

(v) 71 = 5041

(vi) 46 = 2116

Step-by-step explanation:

Identities used: 1: (a + b)² = a² + 2ab + b²

2: (a - b)² = a² - 2ab + b²

i) 32 = (30 + 2)

On squaring:

(30 + 2)² = 900 + 120 + 4 = 1024

(ii) 35 = (30 + 5)

On squaring:

(30 + 5)² = 900 + 300 + 25 = 1225

(iii) 86 = (80 + 6)

On squaring:

(80 + 6)² = 6400 + 960 + 36 = 7396

(iv) 93 = (100 - 7)

On squaring:

(100 - 7)² = 10000 - 1400 + 49 = 8649

(v) 71 = (70 + 1)

On squaring:

(70 + 1)² = 4900 + 140 + 1 = 5041

(vi) 46 = (50 - 4)

On squaring:

(50 - 4)² = 2500 - 400 + 16 = 2116

Answer 2

Answer:

Answers :-

1. Apply identity

• (a + b)² = a² + 2ab + b²

(30² + 2²) = 30² + 2(30)(4)+ 2² = 1024

2. Again same identity

• (a+ b)²= a² + 2ab + b²

(30²+5²) = 30² + 2(30)(5) + 5² = 1225

3. Again Same identity

• (a + b)²= a² + 2ab + b²

(70² + 1²) = 70² + 2(70)(1) + 1² = 5041

4. Apply some different identity

• (a - b)² = a² - 2ab - b²

(50² - 4²) = 50² - 2(50)(4) - 4² = 2116

5. (a - b)² = a² - 2ab - b²

(90² - 4)² = 90² - 2(90)(4) - 4² = 7396

6. (a - b)² = a² - 2ab - b²

(100² - 7²) = 100² - 2(100)(7) - 7² = 8649