Divide and write the result using scientific notation

the 8 and -4 is to the second power

8x10(8)
4x10(-4)

I plugged it in the calculator this way
(8x10^8)/(4x10^-4)
it gave me this as the result
2 E 12

2E12 means 2*10^12 , so your calculation is correct

how would I have known E equals 10. how you get that?

I have been using scientific notation for like 20 years, so I don't remember how I get that, sorry...

To divide numbers written in scientific notation, you can follow these steps:

Step 1: Divide the coefficients (the numbers before the "x") as you would in normal division.
8 ÷ 4 = 2

Step 2: Divide the powers of 10 by subtracting the exponent of the denominator from the exponent of the numerator.
8 - (-4) = 12

Step 3: Determine the sign of the result.
Since the exponent of 10 in the denominator is negative, the result will have a positive exponent of 10.

Putting it all together:
2 x 10^12

Therefore, the result of dividing (8x10^8) by (4x10^-4) is 2 x 10^12.