Looking for answers? Westonci.ca is your go-to Q&A platform, offering quick, trustworthy responses from a community of experts. Find reliable answers to your questions from a wide community of knowledgeable experts on our user-friendly Q&A platform. Discover in-depth answers to your questions from a wide network of professionals on our user-friendly Q&A platform.
Sagot :
Step-by-step explanation:
[tex] \bf \underline{Given \:Question-} \\ [/tex]
[tex]\textsf{Resolve in to factors }[/tex]
[tex] \sf \: {\bigg(\displaystyle\sum_{x,y,z}\rm x\bigg)}^{3} - \displaystyle\sum_{x,y,z}\rm {x}^{3} [/tex]
[tex] \red{\large\underline{\sf{Solution-}}}[/tex]
Given expression is
[tex]\rm :\longmapsto\: \: {\bigg(\displaystyle\sum_{x,y,z}\rm x\bigg)}^{3} - \displaystyle\sum_{x,y,z}\rm {x}^{3} [/tex]
can be rewritten as
[tex] \rm \: = \: {(x + y + z)}^{3} - ( {x}^{3} + {y}^{3} + {z}^{3})[/tex]
can be further rewritten as
[tex] \rm \: = \: {(x + y + z)}^{3} - {x}^{3} - {y}^{3} - {z}^{3}[/tex]
[tex] \rm \: = \: [{(x + y + z)}^{3} - {x}^{3}] - [{y}^{3} + {z}^{3}][/tex]
We know,
[tex]\boxed{\tt{ {x}^{3} + {y}^{3} = (x + y)( {x}^{2} + {y}^{2} - xy)}}[/tex]
and
[tex]\boxed{\tt{ {x}^{3} - {y}^{3} = (x - y)( {x}^{2} + {y}^{2} + xy)}}[/tex]
So, using these Identities, we get
[tex] \rm =(x + y + z - x)[ {(x + y + z)}^{2} + {x}^{2} - x(x + y + z)] - (y + z)( {y}^{2} + {z}^{2} - yz)[/tex]
[tex] \rm =(y + z)[ {(x + y + z)}^{2} + {x}^{2} + {x}^{2} + xy + xz] - (y + z)( {y}^{2} + {z}^{2} - yz)[/tex]
[tex] \rm =(y + z)[ {(x + y + z)}^{2} + {2x}^{2} + xy + xz] - (y + z)( {y}^{2} + {z}^{2} - yz)[/tex]
[tex] \rm =(y + z)[ {(x + y + z)}^{2} + {2x}^{2} + xy + xz - {y}^{2} - {z}^{2} + yz][/tex]
[tex] \rm =(y + z)[ {x}^{2}+{y}^{2}+{z}^{2} + 2xy + 2yz + 2zx + {2x}^{2} + xy + xz - {y}^{2} - {z}^{2} + yz][/tex]
[tex] \rm =(y + z)[3{x}^{2} + 3xy + 3yz + 3zx][/tex]
[tex] \rm \: = \: 3(y + z)( {x}^{2} + xy + yz + zx)[/tex]
[tex] \rm \: = \: 3(y + z)[x(x + y) + z(x + y)][/tex]
[tex] \rm \: = \: 3(y + z)[(x + y)(x + z)][/tex]
[tex] \rm \: = \: 3(y + z)(x + y)(x + z)[/tex]
Hence,
[tex] \boxed{\tt{ \sf {\bigg(\displaystyle\sum_{x,y,z}\rm x\bigg)}^{3} - \displaystyle\sum_{x,y,z}\rm {x}^{3} = 3(x + y)(y + z)(z + x)}}[/tex]
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
More Identities to know:-
(a + b)² = a² + 2ab + b²
(a - b)² = a² - 2ab + b²
a² - b² = (a + b)(a - b)
(a + b)² = (a - b)² + 4ab
(a - b)² = (a + b)² - 4ab
(a + b)² + (a - b)² = 2(a² + b²)
(a + b)³ = a³ + b³ + 3ab(a + b)
(a - b)³ = a³ - b³ - 3ab(a - b)
Thanks for stopping by. We are committed to providing the best answers for all your questions. See you again soon. Thank you for your visit. We're dedicated to helping you find the information you need, whenever you need it. We're here to help at Westonci.ca. Keep visiting for the best answers to your questions.