Thanks to CPhill, AZIZ, Melody (hopefully i didnt leave out anyone) for answering so well! Now...some more Logarithims....

  $$3^{2x} = 27 3^{2x} = 3^3 2x = 3 \mathbf{x = 3/2.}$$

$$3^{-2x+2} = 81 3^{-2x+2} = 3^4 -2x+2 = 4 -2x = 2 x = -1.$$

$$4^{x} = 19 log 4^{x} = log 19 x log 4 = log 19 x = log 19 \div\;log 4. x = 2.1239637567217926.$$

3^x - 1 = 72

3^x = 73

log(3^x) = log 73

x log 3 = log 73

x = log 73 / log 3 

x = 3.9053444835847247.

$$log(2x) = -1 10^{log(2x)} = 10^-1 2x = 0.1 x = 0.1 \div \; 2 x = 0.05.$$

$$log(x) - log(3) = 8 log(x \div \; 3) = 8 10^{(log(x \div \; 3)} = 10^8 x \div \; 3 = 10^8 x = 3*10^8 x = 300000000.$$