Factorise : 2u3-3u2-17u+30

Asked by nisha_vini29 | 25th Feb, 2019, 03:19: PM

Expert Answer:

begin mathsize 16px style straight p left parenthesis straight u right parenthesis space equals space 2 straight u cubed minus 3 straight u squared minus 17 straight u plus 30
space Let space us space assume space that space straight u space equals 2 space is space straight a space zero space of space the space given space cubic space polynomial. space space space left parenthesis space By space trial space and space error space method right parenthesis
straight p left parenthesis 2 right parenthesis space equals space 2 left parenthesis 2 right parenthesis cubed minus 3 left parenthesis 2 right parenthesis squared minus 17 left parenthesis 2 right parenthesis plus 30 space equals space 16 space minus space 12 space minus space 34 space plus space 30 space equals space space 0
Therefore space by space Factor space Theorem comma space left parenthesis straight u space minus space 2 right parenthesis space is space straight a space factor space of space straight p left parenthesis straight u right parenthesis.

Long space Division space Method colon


end style
begin mathsize 16px style straight p left parenthesis straight u right parenthesis space equals space left parenthesis straight u space minus space 2 right parenthesis space left parenthesis 2 straight u squared space plus space straight u space minus space 15 right parenthesis space equals space left parenthesis straight u space minus space 2 right parenthesis space left parenthesis 2 straight u space minus space 5 right parenthesis space left parenthesis straight u space plus space 3 right parenthesis end style

Answered by Yasmeen Khan | 25th Feb, 2019, 04:12: PM