Question

Factorise: 2x² + x - 45​

Answer 1

Step-by-step explanation:

ANSWER

Consider 2x2+x−45

Factor formula x=2a−b±b2−4ac

Here a=2,b=1,c=−45

∴x=4−1±1+360

        =4−1±361

        =4−1±19

∴x=4−1+19,4−1−19

⇒x=418,4−20

⇒x=29,−5

∴2x2+x−45=(2x−9)(x+5)

Answer 2

Answer:

2x²+x-45

=2x²+10x-9x-45

=2x(x+5)-9(x+5)

=(2x-9)(x+5)