$a)34093=3\cdot {10}^4+4\cdot {10}^3+9\cdot {10}^1+3\cdot {10}^0$

$b)45000371=4\cdot {10}^7+5\cdot {10}^6+3\cdot {10}^2+7\cdot {10}^1+1\cdot {10}^0$

$c)4,07=4\cdot {10}^0+7\cdot {10}^{-2}$

$d)18,306=1\cdot {10}^1+8\cdot {10}^0+3\cdot {10}^{-1}+6\cdot 10\left(-3\right)$

$e)0,3208=3\cdot {10}^{-1}+2\cdot {10}^{-2}+8\cdot {10}^{-4}$