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Persamaan kuadrat akar-akarnya dan . Persamaan kuadrat yang akar-akarnya dan adalah ..

Pertanyaan

Persamaan kuadrat 2 x squared minus x plus 5 equals 0 spaceakar-akarnya x subscript 1 dan x subscript 2. Persamaan kuadrat yang akar-akarnya open parentheses x subscript 1 plus 2 close parentheses dan open parentheses x subscript 2 plus 2 close parentheses adalah ..

  1. 2 x squared minus 9 x plus 15 equals 0

  2. 2 x squared minus 8 x plus 15 equals 0

  3. 2 x squared minus 7 x plus 15 equals 0

  4. 2 x squared minus 6 x plus 15 equals 0

  5. 2 x squared minus 5 x plus 15 equals 0

Pembahasan Soal:

Persamaan kuadrat 2 x squared minus x plus 5 equals 0 spaceakar-akarnya x subscript 1 dan x subscript 2. Maka,

table attributes columnalign right center left columnspacing 0px end attributes row cell 2 x squared minus x plus 5 end cell equals cell 0 space end cell row cell a x squared plus b x plus c end cell equals 0 row a equals 2 row b equals cell negative 1 end cell row c equals 5 row blank blank blank row cell x subscript 1 plus x subscript 2 end cell equals cell negative b over a end cell row blank equals cell fraction numerator negative left parenthesis negative 1 right parenthesis over denominator 2 end fraction end cell row blank equals cell 1 half end cell row blank blank blank row cell x subscript 1 times x subscript 1 end cell equals cell c over a end cell row blank equals cell 5 over 3 end cell end table

Persamaan kuadrat yang akar-akarnya open parentheses x subscript 1 plus 2 close parentheses dan open parentheses x subscript 2 plus 2 close parentheses  :

table attributes columnalign right center left columnspacing 0px end attributes row cell x squared minus open square brackets open parentheses x subscript 1 plus 2 close parentheses plus open parentheses x subscript 2 plus 2 close parentheses close square brackets x plus open square brackets open parentheses x subscript 1 plus 2 close parentheses cross times open parentheses x subscript 2 plus 2 close parentheses close square brackets end cell equals 0 row cell x squared minus open square brackets x subscript 1 plus x subscript 2 plus 2 plus 2 close square brackets x plus open square brackets x subscript 1 x subscript 2 plus 2 x subscript 1 plus 2 x subscript 2 plus 4 close square brackets end cell equals 0 row cell x squared minus open square brackets x subscript 1 plus x subscript 2 plus 4 close square brackets x plus open square brackets x subscript 1 x subscript 2 plus 2 left parenthesis x subscript 1 plus x subscript 2 right parenthesis plus 4 close square brackets end cell equals 0 row cell x squared minus open square brackets 1 half plus 4 close square brackets x plus open square brackets 5 over 2 plus 2 left parenthesis 1 half right parenthesis plus 4 close square brackets end cell equals 0 row cell x squared minus open square brackets 1 half plus 8 over 2 close square brackets x plus open square brackets 5 over 2 plus 2 over 2 plus 8 over 2 close square brackets end cell equals 0 row cell x squared minus open square brackets 9 over 2 close square brackets x plus open square brackets 15 over 2 close square brackets end cell equals cell 0 space left parenthesis dikali space 2 right parenthesis end cell row cell 2 x squared minus 9 x plus 15 end cell equals 0 end table

Oleh karena itu, jawaban yang benar adalah A.

Pembahasan terverifikasi oleh Roboguru

Terakhir diupdate 04 Juni 2021

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