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Jumlah akar-akar persamaan ( 9 1 ​ ) 1 + x 2 = 2 7 x 2 − 5 x − 4 adalah..

Jumlah akar-akar persamaan adalah..

  1. 5

  2. 3

  3. 2

  4. negative 2

  5. negative 3

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N. Puspita

Master Teacher

Jawaban terverifikasi

Jawaban

jawaban yang tepat adalah B

jawaban yang tepat adalah B

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Pembahasan

Pembahasan
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Ingat kembali: Jika Pertama kita ubah: Sehingga diperoleh perhitungan: Maka, Jumlah akar-akar persamaan: Dengan demikian, Jumlah akar-akar persamaan adalah Jadi, jawaban yang tepat adalah B

Ingat kembali:

a to the power of n equals stack stack a cross times a cross times a cross times... cross times a with underbrace below with a space s e b a n y a k space n below comma space a not equal to 0 

1 over a to the power of n equals a to the power of negative n end exponent comma space a not equal to 0 

open parentheses a to the power of m close parentheses to the power of n equals a to the power of m times n end exponent comma space a not equal to 0 

a to the power of f open parentheses x close parentheses end exponent equals a to the power of g open parentheses x close parentheses end exponent rightwards arrow f open parentheses x close parentheses equals g open parentheses x close parentheses

Jika  f open parentheses x close parentheses equals a x squared plus b x plus c comma space maka space x subscript 1 plus x subscript 2 equals fraction numerator negative b over denominator a end fraction

Pertama kita ubah:

9 equals 3 cross times 3 equals 3 squared

27 equals 3 cross times 3 cross times 3 equals 3 cubed

Sehingga diperoleh perhitungan:

table attributes columnalign right center left columnspacing 0px end attributes row cell open parentheses 1 over 9 close parentheses to the power of 1 plus x squared end exponent end cell equals cell 27 to the power of x squared minus 5 x minus 4 end exponent end cell row cell open parentheses 1 over 3 squared close parentheses to the power of 1 plus x squared end exponent end cell equals cell open parentheses 3 cubed close parentheses to the power of x squared minus 5 x minus 4 end exponent end cell row cell open parentheses 3 to the power of negative 2 end exponent close parentheses to the power of 1 plus x squared end exponent end cell equals cell 3 cubed to the power of open parentheses x squared minus 5 x minus 4 close parentheses end exponent end cell row cell 3 to the power of negative 2 end exponent open parentheses blank to the power of 1 plus x squared end exponent close parentheses end cell equals cell 3 cubed to the power of x squared minus 15 x minus 12 end exponent end cell row cell 3 to the power of negative 2 minus 2 x squared end exponent end cell equals cell 3 cubed to the power of x squared minus 15 x minus 12 end exponent comma space sehingga end cell row cell negative 2 minus 2 straight x squared end cell equals cell 3 straight x squared minus 15 straight x minus 12 end cell row cell negative 2 minus 2 straight x squared minus 3 straight x squared plus 15 straight x plus 12 end cell equals 0 row cell negative 5 straight x squared plus 15 straight x plus 10 end cell equals 0 row blank blank cell a equals negative 5 comma space b equals 15 comma space c equals 10 end cell end table  

Maka, Jumlah akar-akar persamaan:

table attributes columnalign right center left columnspacing 0px end attributes row cell x subscript 1 plus x subscript 2 end cell equals cell fraction numerator negative b over denominator a end fraction end cell row blank equals cell fraction numerator negative open parentheses 15 close parentheses over denominator open parentheses negative 5 close parentheses end fraction end cell row blank equals 3 end table 

Dengan demikian, Jumlah akar-akar persamaan open parentheses 1 over 9 close parentheses to the power of 1 plus x squared end exponent equals 27 to the power of x squared minus 5 x minus 4 end exponent adalah 3

Jadi, jawaban yang tepat adalah B

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