# How do you simplify and write (1.0times10^-15)/(4.2times10^-7) in scientific notation?

Jul 27, 2016

$2.38 \cdot {10}^{-} 9$

#### Explanation:

How I usually answer questions like this I ignore the exponents first and divide the numbers as usual
$\frac{1.0}{4.2} = 0.238$

Now I take care of the exponents since we're dividing you subtract the exponents
$- 15 - \left(- 7\right) = - 8$

So now we have
$0.238 \cdot {10}^{-} 8$

We have to move the decimal back to make it proper scientific notation, so the answer is
$2.38 \cdot {10}^{-} 9$