Question

What is 7.09 x 10^5 - 6.10 x 10^4 in scientific notation

Answer 1

If you want to subtract them in scientific notation, first you need to make both exponents equal. One of them is raised to 5 and the other is raised to 4. 

$7.09$ x $10^{5}$

$6.10$ x $10^{4}$ 

To make the first one raised to four, all you need to do is move the decimal to the right. The new notation will then be:

$70.9$ x $10^{4}$

Now all you need to do is line up the decimals like you would normally and then subtract. Also copy the $10^{4}$

$70.9$ x $10^{4}$
-$6.10$ x $10^{4}$ 
=
$64.8$ x $10^{4}$

Then we to make it in standard form, just move the decimal to the left and add 1 to the exponent. 

$6.48$ x $10^{5}$