Question

1) Resolva as equações

Answer 1

a)3^(x-1)=81
3^(x-1)=3^4
X-1=4
x=4+1
x=5
b)(1/2)^x = ³/¨¨4
(2^(-1))^x=2^(2/3)
2^(-x)=2^(2/3)
-x=2/3  *(-1)
x=-2/3
c)0,75^x=9/16
(4/3)^x=3^2/4^2
(4/3)^x=(3/4)^2
x=2
d)9^(x+1) =1/3^3
9^(x+1) = 3^(-3)
x+1=-3
x=-3-1
x=-4
e)2^(x^2 -3x -4)=1
2^x= y
(2^x)^x    *   (2^x)^-3   *   (2^1)^-4=1
x-3-4=1
x-7=1
x=1+7
x=8