nilai x yang memenuhi persamaan 3^x+2 + 9^x+1 =810 adalah...

3^x+2+9^x+1=810
3^x+2+(3^2)x+1=810
3^x+2+3^2x+2=810
3^×+2+3^2x+2=(3^6)(3^4)
X+2+2x+2=6+4
X+2x =10+2+2
3x=14
X=14/3
X=4 2/3

[tex]3 ^{x + 2} + {9}^{x + 1} = 810 \\ {3}^{x + 2} + ( { {3}^{2}) }^{x + 1} = 810 \\ {3}^{x + 2} + {3}^{2x + 2}= 810 \\ {3}^{x} . {3}^{2} + {3}^{2x}. {3}^{2} = 180\\ misalkan \\ y = {3}^{x} \\ maka \\ {3}^{2} y + {3}^{2} {y}^{2} = 810 \\ 9 {y}^{2} + 9y = 810 \\ {y}^{2} + y = 90[/tex]

lanjut ke subsitusi kenilai x tadi