Can anyone help me with my math homework?

Question

Can anyone help me with the following problems:

1. 0.00045 times 8000 Divide by 40,000. Write answer in scientific notation

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Answer 1

0.00045 * 8000 / 40000

4.5e-4 * 8e3 / 4e4

first part ...

4.5e-4 * 8e3

4.5 * 8= 36 or 3.6e1

e-4 + e+3 = e-1

but calc of numbers cause a left shift of 1 decimal place ... so e-1 +e1 = e0

3.6e0

second part ...

3.6e0 / 4e4

3.6 / 4 = .9 or 9e-1

e0 - e4 = e-4

but the calc of the number caused a right shift of 1 decimal place ... e-1 + e-4 = e-5

So the answer is ...

9e-5

Answer 2

0.00045 times 8000 Divide by 40,000

solution:

(0.00045) (8,000) = 3.6

3.6 / 40,000 = 0.00009

0.00009 = 9.0 x 10^-5

going to the right = (-)exponent

going to the left  = (+)exponent

9.0 x 10^-5 -----> ans

Answer 3

it's 9x10^-5. check your calc