Explicație pas cu pas:
b)
[tex]{3}^{x} = 81 \iff {3}^{x} = {3}^{4} \\ \implies \ x = 4[/tex]
c)
[tex]{9}^{2x} = {81}^{4} \iff {( {9}^{2} )}^{x} = {({9}^{2})}^{4} \\ \implies x = 4[/tex]
d)
[tex]{8}^{3x} = {64}^{3} \iff {8}^{3x} = {( {8}^{2} )}^{3} \\ {( {8}^{3} )}^{x} = {( {8}^{3} )}^{2} \implies x = 2[/tex]
f)
[tex]{3}^{x + 2} + {3}^{x} = 270[/tex]
[tex]{3}^{x}( {3}^{2} + 1) = 270 \\ [/tex]
[tex]{3}^{x} \cdot 10 = 270[/tex]
[tex]{3}^{x} = 27[/tex]
[tex]{3}^{x} = {3}^{3} \implies x = 3[/tex]
