Răspuns:
1.
81=3^4 =>5x+4=4 =>x=0
2.
1/64 = 4^(-3) =>2x+3=(-3) =>x=(-3)
3.
64=2^6 =>x^2 - 3 = 6 =>x=3 sau -3
4.
125=5^3 ; 25=5^2 =>2x=3 =>x=3/2
5.
5^x•(5^2 - 1)=24; 5^x•24=24 =>5^x = 1 =>x=0
6.
2^(x+1)•(2^2 + 1)=40 =>2^(x+1)•5=40 =>2^(x+1)=8
8=2^3 =>x+1=3 =>x=2
7.
27=3^3 =>x^2 - 2x - 3 = 0
delta = (-2)^2 - 4•1•(-3) = 16 =>rad.delta = 4
x1 = (2-4)/2 = (-1)
x2 = (2+4)/2 = 3
