Factorise:
Question:

Factorise:
x2 − 11x − 42

Solution:

The given expression is $x^{2}-11 x-42$.

Find two numbers that follow the conditions given below :

Sum $=-11$

Product $=-42$

Clearly, the numbers are $-14$ and 3 .

$x^{2}-11 x-42=x^{2}-14 x+3 x-42$

$=x(x-14)+3(x-14)$

$=(x-14)(x+3)$