# How do you simplify ((9 x 10^9) x (1.65 x 10^-8) x (5.1 x 10^-8)) / (.555)^2?

Apr 6, 2015

You multiply the numbers, then you add the $10$-powers:

We first work out the part above the division bar:
$\left(9 \cdot {10}^{9}\right) \left(1.65 \cdot {10}^{-} 8\right) \left(5.1 \cdot {10}^{-} 8\right) =$
$\left(9 \cdot 1.65 \cdot 5.1\right) \left({10}^{9} \cdot {10}^{-} 8 \cdot {10}^{-} 8\right) =$
$76.58 \cdot {10}^{9 - 8 - 8} = 76.58 \cdot {10}^{-} 6$

The numerator:
${.555}^{2} = 0.308$

And then:
$\left(76.58 / 0.308\right) \cdot {10}^{-} 6 = 249 \cdot {10}^{-} 6 =$

Move decimal point two to the left, so power goes up (means less negative):

Answer : $2.49 \cdot {10}^{-} 4$