Question

The factors of 3x^2- x - 4 are:
(a) (3x – 4)(x - 1)
(b) (3x - 4)(x + 1)
(c) (3x + 4)(x - 1)
(d) (3x + 4)(x + 1)

Answer 1

Question :

• The factors of 3x² - x - 4 are:

Solution :

⇒ 3x² - x - 4

By splitting middle term

⇒ 3x² - 4x + 3x - 4

⇒ x ( 3x - 4 ) + 1 ( 3x - 4 )

⇒ ( 3x - 4 ) ( x + 1 )

Option ( b ) is correct

Answer 2

The factors of 3x²- x - 4 are:

(a) (3x – 4)(x - 1)

(b) (3x - 4)(x + 1)

(c) (3x + 4)(x - 1)

(d) (3x + 4)(x + 1)

Explanation :

↝3x² - 4x + 3x - 4 [ By middle term factorisation]

↝x ( 3x - 4 ) + 1 ( 3x - 4)

↝( 3x - 4 ) ( x + 1 )