Answered

IDNLearn.com provides a seamless experience for finding accurate answers. Our community is here to provide the comprehensive and accurate answers you need to make informed decisions.

PLEASEEE HELP. Solve x^3-7x^2+6x-42=0

Sagot :

Eternal3fearidn
factor by grouping

x^2(x-7) + 6(x-7) = 0   [took x^2 out of the first two and a 6 out of the last two]
(x-7)(x^2+6) = 0     [moved (x-7) out to the front]
x = -i sqrt(6) , i sqrt(6) , 7

only one real solution of x = 7
[tex] x^{3} -7 x^{2} +6x-42=0[/tex]

[tex](x-7) [/tex] is a factor since it is a factor of -42 and 7 is a solution for f(x) to equal 0.

[tex](x-7)(a x^{2} +bx+c)=0[/tex]

[tex](x-7)( x^{2} +bx+6)=0[/tex]

[tex]-7 x^{2} +b x^{2} =-7 x^{2} [/tex]

[tex]-7+b=-7[/tex]

[tex]b=0[/tex]

[tex](x-7)( x^{2} +6)=0[/tex]

[tex]x-7=0[/tex]

[tex] x^{2} +6=0[/tex]

[tex]x=7[/tex] (only solution because you can't square root (-6))


Thank you for using this platform to share and learn. Don't hesitate to keep asking and answering. We value every contribution you make. Thank you for choosing IDNLearn.com for your queries. We’re committed to providing accurate answers, so visit us again soon.