Answer
$6.0\times(10^{-5})$
Work Step by Step
Using scientific notation and the laws of exponents, the given expression, $
\dfrac{2000\times0.000021}{700}
,$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{(2.0\times10^3)\times(2.1\times10^{-5})}{7.0\times10^2}
\\\\=
(2\cdot2.1\div7.0)\times(10^3\cdot10^{-5}\div10^2)
\\\\=
0.6\times(10^{3+(-5)-2})
\\\\=
0.6\times(10^{-4})
\\\\=
6.0\times(10^{-5})
.\end{array}
