Question

What is the value of expression?

5−8 • 5−4
8 and 4 exponents @jim_thompson5910

Answer 1

so you have

\[\Large 5^{-8} * 5^{-4}\]

right?

Answer 2

yes

Answer 3

the bases are both 5

when you multiply two exponential expressions like this, with the same base, you add the exponents

Answer 4

\[\Large 5^{-8} * 5^{-4} = 5^{-8 + (-4)} = ??\]

Answer 5

32?

Answer 6

how are you getting 32?

Answer 7

the next step you need to do is to add the exponents -8 and -4 to get ???

Answer 8

12

Answer 9

-12

Answer 10

\[\Large 5^{-8} * 5^{-4} = 5^{-8+(-4)} = 5^{-12}\]

what is the last step?

Answer 11

umm oh man idek

Answer 12

what does a negative exponent tell you?

Answer 13

think back to \(\Large 7^{-3}\)

Answer 14

repeated divison?

Answer 15

it means that you flip the fraction 5/1 to get 1/5 to get a positive exponent

\[\Large 5^{-12} = \frac{1}{5^{12}}\]

Answer 16

So,

\[\Large 5^{-8} * 5^{-4} = \frac{1}{5^{12}}\]

I'm not going to evaluate 5^12 since that number is so very big. So I'll just leave it as 5^12

Answer 17

oooh okay