Question

Factorise: x² – 22x + 117

Answer 1

First find the two numbers whose sum= -22 and product=117

Clearly, the numbers are 13 and 9

∴ we get, x² – 22x + 117 

= x² – 13x – 9x + 117

= x(x-13) – 9(x-13)

= (x-13) (x-9)