Question

Factorise:

3x² – x – 4

Answer 1

We can find two numbers such that pq = 3 × (−4) = −12 and p + q = −1

They are p = −4 and q = 3

Here, 3x² − x − 4

= 3x² − 4x + 3x − 4

= x (3x − 4) + 1 (3x − 4)

= (3x − 4) (x + 1)