Factorise: a^3-a-120

Asked by laxmi.agarwal055 | 21st Feb, 2018, 08:35: PM

Expert Answer:

begin mathsize 16px style straight a cubed minus straight a minus 120
equals straight a cubed minus 125 minus straight a plus 5
equals open parentheses straight a minus 5 close parentheses open parentheses straight a squared plus 5 straight a plus 25 close parentheses minus left parenthesis straight a minus 5 right parenthesis
equals left parenthesis straight a minus 5 right parenthesis left parenthesis straight a squared plus 5 straight a plus 25 minus 1 right parenthesis
equals left parenthesis straight a minus 5 right parenthesis left parenthesis straight a squared plus 5 straight a plus 24 right parenthesis end style

Answered by Sneha shidid | 22nd Feb, 2018, 10:40: AM