Question

please help me in MCQ please answer please tell correct answer please don't play please tell correct answer​

Answer 1

Answer: 1. b = 1/4 (c). 2. (c) 3abc.

Explanation:

1. Given that,

49x^2 - b = (7x + 1/2)(7x - 1/2)

Simplifying the RHS:-

(7x + 1/2)(7x - 1/2)

= (7x)^2 - (1/2)^2

= 49x^2 - 1/4

Since, 49x^2 - b ⇔ 49x^2 - 1/4, so by comparing b = 1/4. (c).

2. Given that (a + b + c) = 0.

We know,

a^3 + b^3 + c^3 - 3abc = (a + b + c)(a^2 + b^2 + c^2 - ab - bc - ca)

⇒ a^3 + b^3 + c^3 - 3abc = 0.(a^2 + b^2 + c^2 - ab - bc - ca)

⇒a^3 + b^3 + c^3 = 3abc (c).