Question

Resolva as equações exponenciais
A) 3×+³ 81
B) 2×=8
C)5×-3=5²

Answer 1

a) 3^x+3=81
     3^x+3=3^4
       x+3=4
       x=4-3=1

b) 2^x=8
    2^x=2^3
      x=3

c)5^x-3=5^2

x-3=2
x=2+3

x=5

Answer 2

$\large\boxed{\begin{array}{l}\sf A)~\rm 3^{x+3}=81\\\rm 3^{x+3}=3^4\\\rm x+3=4\\\rm x=4-3\\\rm x=1\\\sf B)~\rm 2^x=8\\\rm 2^x=2^3\\\rm x=3\\\sf C)~\rm5^{x-3}=5^2\\\rm x-3=2\\\rm x=2+3\\\rm x=5\end{array}}$