jika log (logx) =log (log (2+y)) + log 2 dan log (x-8) =2 log y, maka nilai 2x +3y adalah
Matematika
putrialinaziah5497
Pertanyaan
jika log (logx) =log (log (2+y)) + log 2 dan log (x-8) =2 log y, maka nilai 2x +3y adalah
1 Jawaban
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1. Jawaban hendrisyafa
Log (log x) = log (2. Log (2+y))
Log x = 2 log (2+y)
= log (2+y)²
x = (2+y)².....pers 1
Log (x-8) = log y²
x-8. = y² ....pers 2
Pers 1 ke 2
(2+y)²-8 = y²
4+4y+y²-8 = y²
4y = 4
y = 1
Pers 1
x = (2+1)²
= 9
2x+3y = 2(9)+3(1)
= 18+3
= 21