## anonymous 5 years ago Simplify the expression, and write answer in scientific notation

1. anonymous

where is the expression?

2. anonymous

$\left( 4.2 \times 10^{-8} \right) \left( 2.4 \times 10^{5} \right)/ 2.4 \times 10^{3}$

3. anonymous

hold on

4. anonymous

it's suppose to be a fraction (......) over 2.4 blah blah

5. anonymous

I see it

6. anonymous

the dash is the fraction line, right?

7. anonymous

8. anonymous

Ohhh okay!

9. anonymous

yes. thank you <3

10. anonymous

Anytime!

11. anonymous

ANSWER: 0.0000042 (.000000042)(240, 000) ____________________________ (2400)

12. anonymous

lmao what?

13. anonymous

Do you know how to find standard notation? And the dashes represent the fraction line.

14. anonymous

I divided top over bottom

15. anonymous

so what is the final answer?

16. anonymous

2400?

17. anonymous

18. anonymous

${(4.2\times10^{-8})(2.4\times10^{5}) \over 2.4\times10^3}=4.2\times10^{-6}$

19. anonymous

i have to write that answer in scientific notation, that isn't the right answer. it says it's wrong.

20. anonymous

OH I'M SORRY. Then you change the answer I gave you to how many zeros are behind 4. AnwarA is correct.

21. anonymous

thank you anwara

22. anonymous

and thank you OMGirene for the help :]

23. anonymous

Oh, no problem! Sorry for making a mistake.

24. anonymous

can you explain how you got that pls?

25. anonymous

The 2.4 in the top will be cancelled with the one in the bottom. You will be left with 4.8 times some powers of 10's. When you multiply numbers that have the same base you add powers, and when you divide them you subtract powers. So the answer will be $$4.8 \times 10^{-8+5-3}=4.8 \times 10^{-6}$$.