Question

simplify the expression. write the answer using scientific notation. (9x10^7)(7x10^9) 1.6x10^17 1.6x10^64 6.3x10^64 6.3x10^17

Answer 1

$The\ scientific\ notation:a\cdot10^n\ where\ 1\leq a \ \textless \ 10\ and\ n\in\mathbb{Z}\\----------------------------\\\\(9\cdot10^7)(7\cdot10^9)=(9\cdot7)(10^7\cdot10^9)=63\cdot10^{7+9}\\\\=63\cdot10^{16}=6.3\cdot10^{16+1}=6.3\cdot10^{17}$

Answer 2

Answer:

$6.3\times10^{17}$

Step-by-step explanation:

We have to multiply the expression

$(9\times10^7)\times(7\times10^9)$

We can rewrite this multiplication as

$(9\times7(10^7\times10^9)$

Now, use the exponent rule, $x^a\cdot x^b=a^{a+b}$

$63\times10^{7+9}\\\\=63\times10^{16}$

Finally, write in scientific notation

$6.3\times10^{17}$

Last option is correct.