Question

(7.8 x 10-5) x.630Simplify the expressionusing scientific notation and express your answer(4.2 x 10') < (3.9 x 107)in scientific notation. Round your answer to the nearest thousandth.AnswerKeypadKeyboard ShortcuX10

Answer 1

we want to simplify the expression

`((7.8*10^(-5))*630)/((4.2*10^6)*(3.9*10^7))`

We need to write 630 in standard form

`\begin{gathered} \Rightarrow((7.8*10^(-5))*630)/((4.2*10^6)*(3.9*10^7))=((7.8*10^(-5))*(6.3*10^2))/((4.2*10^6)*(3.9*10^7)) \\ \Rightarrow((7.8*6.3)*(10^(-5)*10^2))/((4.2*3.9)*(10^6*10^7))=((78*63)*(10^(-5)*10^2))/((42*39)*(10^6*10^7)) \\ \Rightarrow3*((10^(-5)*10^2))/((10^6*10^7))=3*(10^(-3))/(10^(13))=3*10^(-16) \end{gathered}`

So, to the nearest thousandth would be

`3.000*10^(-16)`