Question

a) Factorise it : x4 + 5x2 + 9​

Answer 1

Answer:

X4 + 5X2 + 9 

 X4 + 5X2  + X2 + 9     -  X2 

 X4 + 6X2  + 9      -  X2   group 3 and factor

 (X2  + 3) (X2  + 3)    -  X2 

 (X2  + 3) 2  -  X2   this is a difference of  squares

 (X2  + 3 – X) (X2  + 3 + X) rearrange

 (X2  – X +3) (X2  + X +3)..

Hope it helps you...