Question

Find the roots of 21x² - 2x + 1/21 = 0 by the factorisation of the corresponding quadratic polynomial.

Answer 1

Given, 21x² - 2x + 1/21 = 0

⇒ 441x² - 42x + 1 = 0

By splitting the middle term,

⇒ 441x² - 21x - 21x + 1 = 0

Taking common in the expression,

⇒ 21x (21x - 1) – 1 (21x - 1) = 0

⇒ (21x - 1) (21 x - 1) = 0

∴ 21x – 1 = 0 and ∴ 21x – 1 = 0

∴ x = 1/21 and ∴ x = 1/21