cara nomor 24 dan 25 gimana? bantu ya

Kelas : X SMA
Mapel : Matematika Peminatan
Bab : Fungsi Eksponensial dan Logaritma
Indikator : Persamaan Eksponensial

Langkah Penyelesaian dan Jawaban :

[tex]3^{4-x} + 3^x = 30 \\ 3^4 \cdot3^{-x} + 3^x - 30 = 0 \\ 81 \cdot \frac{1}{3^x} + 3^x - 30 = 0 \\ \frac{81}{3^x}+3^x - 30 = 0 \\\\ - misal \ 3^x = p \\ \frac{81}{p}+p - 30 = 0 \\ 81 + p^2 - 30p = 0 \\ (p - 27)(p - 3) = 0 \\ p = 27, p = 3 \\ 3^x = 27, 3^x = 3 \\\\ 3^x = 27\\ x = 3 \\\\ 3^x = 3 \\ x = 1 \\\\ x_1^3 +x_2^3 = 3^3 + 1^3 \\ x_1^3 +x_2^3 = 28 \ (D)[/tex]
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[tex] \frac{1}{2} \cdot 4^{x+1} - 5 \cdot 2^x + 2 = 0 \\ \frac{1}{2} \cdot (2^2)^{x+1} - 5\cdot 2^x + 2 = 0 \\ \frac{1}{2} \cdot 2^{2x + 2} - 5\cdot 2^x + 2 = 0 \\ \frac{1}{2} \cdot (2^x)^2 \cdot 2^2 - 5\cdot 2^x + 2 = 0 \\\\ - misal \ 2^x = p \\ \frac{1}{2} \cdot (p)^2 \cdot 4 - 5\cdot p + 2 = 0 \\ 2p^2 - 5p + 2 = 0 \\ (2p - 1) (p - 2) = 0 \\ p = \frac{1}{2}, p = 2 \\ 2^x = \frac{1}{2}, 2^x = 2 \\\\ 2^x = \frac{1}{2} \\ 2^x = 2^{-1} \\ x = - 1 \\\\ 2^x = 2 \\ x = 1 \\\\ HP = \left\{-1,1\right\}[/tex]