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Misalkan nilai  dan  adalah akar-akar persamaan kuadrat . Nilai dari

Pertanyaan

Misalkan nilai begin mathsize 14px style x subscript 1 end style dan begin mathsize 14px style x subscript 2 end style adalah akar-akar persamaan kuadrat begin mathsize 14px style x squared minus 5 x minus 2 equals 0 end style. Nilai dari begin mathsize 14px style 2 over x subscript 1 plus 2 over x subscript 2 equals... end style 

  1. begin mathsize 14px style 5 end style 

  2. begin mathsize 14px style 0 comma 2 end style 

  3. begin mathsize 14px style 0 end style 

  4. begin mathsize 14px style negative 0 comma 5 end style 

  5. begin mathsize 14px style negative 5 end style 

Pembahasan Soal:

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

 

table attributes columnalign right center left columnspacing 0px end attributes row cell 2 over x subscript 1 plus 2 over x subscript 2 end cell equals cell fraction numerator open parentheses 2 times x subscript 1 close parentheses plus open parentheses 2 times x subscript 2 close parentheses over denominator x subscript 1 times x subscript 2 end fraction end cell row blank equals cell fraction numerator 2 open parentheses x subscript 1 plus x subscript 2 close parentheses over denominator x subscript 1 times x subscript 2 end fraction end cell row blank equals cell fraction numerator 2 open parentheses 5 close parentheses over denominator negative 2 end fraction end cell row blank equals cell fraction numerator 10 over denominator negative 2 end fraction end cell row blank equals cell negative 5 end cell end table

Jadi, jawaban yang tepat adalah E.

Pembahasan terverifikasi oleh Roboguru

Terakhir diupdate 17 Juni 2021

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