3^x+ 3^5-x = 36 ..tolong bantu jawab ya kak :)
Matematika
Yhaya0405
Pertanyaan
3^x+ 3^5-x = 36 ..tolong bantu jawab ya kak :)
2 Jawaban
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1. Jawaban Anonyme
jawab
3ˣ + 3⁵⁻ˣ = 36
3ˣ + 3⁵.3⁻ˣ = 36
misalkan 3ˣ = a
a + 243/a = 36....kalikan a
a² + 243 = 36a
a² - 36 a + 243 = 0
(a - 27)(a - 9) = 0
a = 27 atau a = 9
3ˣ = a
a= 27 → 3ˣ = 27 = 3³
x = 3
a= 9 → 3ˣ = 9 = 3²
x = 2
HP x = (2, 3) -
2. Jawaban ahreumlim
3ˣ + 3⁵⁻ˣ = 36
3ˣ + 3⁵ . 3⁻ˣ = 36 (kalikan dengan 3ˣ)
3²ˣ + 3⁵ = 36 . 3ˣ
3²ˣ - 36. 3ˣ + 243 = 0
misalkan
y = 3ˣ , maka
y² - 36y + 243 = 0
(y - 9)(y - 27) = 0
y = 9 y = 27
(i)
y = 9
3ˣ = 9
x = 2
(ii)
y = 27
3ˣ = 27
x = 3
jadi HP = {2 , 3}