Question

do the following maths worksheet:

Answer 1

Answer:

III rd one_ idk

and the 2nd question's 2nd part idk

Answer 2

$\textsf{\large{\underline{Question 1}:}}$

i) (a + 2b)²

Using identity (x + y)² = x² + 2xy + y², we get:

= (a)² + (2b)² + 2 × (a) × (2b)

= a² + 4b² + 4ab

= a² + 4ab + 4b² (Answer)

ii) (5x - 3y)²

Using identity (a - b)² = a² - 2ab + b², we get:

= (5x)² + (3y)² - 2 × (5x) × (3y)

= 25x² + 9y² - 30xy

= 25x² - 30xy + 9y² (Answer)

iii) (3a + 4)(3a - 4)(9a² + 16)

Using identity (x + y)(x - y) = x² - y², we get:

= [(3a)² - (4)²][9a² + 16]

= (9a² - 16)(9a² + 16)

= (9a²)² - (16)²

= 81a⁴ - 256 (Answer)

$\textsf{\large{\underline{Question 2}:}}$

Given:

→ a² + b² = 73

→ ab = 24

We know that:

→ (a + b)² = a² + 2ab + b²

→ (a + b)² = 73 + 2 × 24

→ (a + b)² = 73 + 48

→ (a + b)² = 121

→ (a + b) = √121 = ±11 – (i)

Again:

→ (a - b)² = a² - 2ab + b²

→ (a - b)² = 73 - 48

→ (a - b)² = 25

→ (a - b)² = √25 = ±5 – (ii)

Which is our required answer.