CBSE Class 9 Answered
Q: Use suitable identity to find the following product.
(Question from Polynomials chapter, question is attached below in the image (PNG)
Experts Please help...........)
Asked by prakash.sanyasi | 28 Dec, 2019, 04:59: AM
Expert Answer
(x+y+z)(x²+y²+z²-xy-yz-zx)=x³+y³+z³-3xyz.....(1)
Now,
(a-b-c)(a²+b²+c²+ab-bc+ca)
=[a+(-b)+(-c)][a²+(-b)²+(-c)²-a(-b)-(-b)(-c)-(-c)a]
= a³+(-b)³+(-c)³-3a(-b)(-c)
= a³-b³-c³-3abc.......From (1)
Therefore,
(a-b-c)(a²+b²+c²+ab-bc+ca)=a³-b³-c³-3abc
Now,
(a-b-c)(a²+b²+c²+ab-bc+ca)
=[a+(-b)+(-c)][a²+(-b)²+(-c)²-a(-b)-(-b)(-c)-(-c)a]
= a³+(-b)³+(-c)³-3a(-b)(-c)
= a³-b³-c³-3abc.......From (1)
Therefore,
(a-b-c)(a²+b²+c²+ab-bc+ca)=a³-b³-c³-3abc
Answered by Arun | 28 Dec, 2019, 08:44: AM
Application Videos
Concept Videos
CBSE 9 - Maths
Asked by sumithra.suresh1 | 18 Jun, 2022, 05:15: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by tabhinav666 | 15 May, 2022, 05:54: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by shreya.khairnar2007 | 02 Apr, 2022, 06:13: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by mohammad.muntazir.the.legend | 07 Mar, 2022, 04:05: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by saakshigoel207 | 04 Jun, 2021, 08:19: PM
ANSWERED BY EXPERT
CBSE 9 - Maths
Asked by mohit9949941900 | 28 Feb, 2021, 05:08: PM
ANSWERED BY EXPERT