Question

Factorise: z² + 19z - 150

Answer 1

First find the two numbers whose sum=19 and product= -150

Clearly, the numbers are 25 and 6

∴ we get, z² +19z – 150 

= z² + 25z – 6z – 150

= z(z+25) – 6(z+25)

= (z+25) (z-6)