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Diketahui begin mathsize 14px style f open parentheses x plus 5 close parentheses equals 3 x squared plus 10 x minus 3 end style dan begin mathsize 14px style g open parentheses 4 x minus 1 close parentheses equals fraction numerator 1 minus 8 x over denominator 2 x plus 2 end fraction. end style Tentukan hasil berikut

a. begin mathsize 14px style f open parentheses x close parentheses end style dan begin mathsize 14px style g open parentheses x close parentheses end style 

Pembahasan Video:

Pembahasan Soal:

misalkan

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell x plus 5 end cell equals m row x equals cell m minus 5 end cell end table end style 

table attributes columnalign right center left columnspacing 0px end attributes row cell f open parentheses m minus 5 plus 5 close parentheses end cell equals cell 3 open parentheses m minus 5 close parentheses squared plus 10 left parenthesis m minus 5 right parenthesis minus 3 end cell row blank equals cell space 3 left parenthesis m squared minus 10 m plus 25 right parenthesis plus 10 m minus 50 minus 3 end cell row blank equals cell space 3 m squared minus 30 m plus 75 plus 10 m minus 53 end cell row cell f open parentheses m close parentheses end cell equals cell 3 m squared minus 20 m plus 22 end cell end table

ganti m equals x  

f open parentheses x close parentheses equals 3 x squared minus 20 x plus 22  

Misalkan 

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell 4 x minus 1 end cell equals n row cell 4 x end cell equals cell n plus 1 end cell row x equals cell fraction numerator n plus 1 over denominator 4 end fraction end cell end table end style 

table attributes columnalign right center left columnspacing 0px end attributes row cell g open parentheses 4 open parentheses fraction numerator n plus 1 over denominator 4 end fraction close parentheses minus 1 close parentheses end cell equals cell fraction numerator 1 minus 8 open parentheses begin display style fraction numerator n plus 1 over denominator 4 end fraction end style close parentheses over denominator 2 open parentheses fraction numerator n plus 1 over denominator 4 end fraction close parentheses plus 2 end fraction end cell row blank equals cell fraction numerator 1 minus 2 n minus 2 over denominator begin display style fraction numerator n plus 1 over denominator 2 end fraction plus 2 end style end fraction end cell row blank equals cell fraction numerator negative 2 n minus 1 over denominator begin display style fraction numerator n plus 5 over denominator 2 end fraction end style end fraction end cell row cell g open parentheses n close parentheses end cell equals cell fraction numerator negative 4 n minus 2 over denominator n plus 5 end fraction end cell end table  

ganti n equals x  

g open parentheses x close parentheses equals fraction numerator negative 4 x minus 2 over denominator x plus 5 end fraction  

Jadi, begin mathsize 14px style f open parentheses x close parentheses end style dan begin mathsize 14px style g open parentheses x close parentheses end style adalah 3 x squared minus 20 x plus 22 dan fraction numerator negative 4 x minus 2 over denominator x plus 5 end fraction.  

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Terakhir diupdate 05 Mei 2021

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