Question

Please help with my math questions!!!



What is the value of expression?
5^-8 * 5^-4


A.
5^32

B.
5^4

C.
5^−4

D.
5^−12

What is the missing value?

7 (empty box)
-----------
7^5 = 7^-2


A.
7

B.
3

C.
−3

D.
−7

What is the missing exponent?
(2^-5) [please tell number here] = 2^-15

what is the value of the expression?

9^8
--------
9^-4 * 9^10

A.
9^−48

B.
9^−2

C.
9^2

D.
9^22

what is the missing exponent?
5^8
------
{5^-4)^-3 = 5[please type number here]

Answer 1

I got the first question on my own but I need help with the rest

Answer 2

@zimmah

Answer 3

\[\Large \frac{ 7^? }{ 7^5 } = 7^{-2}\]

Answer 4

or in other words \(\Large 7^{?-5} = 7^{-2}\)

Answer 5

or better yet, x-5 = -2

Answer 6

no no no no, I got that already. I need help with 3, 4 and 5.

Answer 7

oh right, i thought you only had the first one

Answer 8

Sorry, forgot to add it :)

Answer 9

\[\Large (2^{-5})^? = 2^{-15}\]

Answer 10

that's how i read the question

Answer 11

I put -10 is that right? where the question mark is

Answer 12

no that would make a much larger number

Answer 13

you are not multiplying them, you are putting them the power of each other.

The rule for that becomes \(\Large (a^n)^q =a^{n*q}\)

Answer 14

it's like (2^3)^2 is like (2*2*2)^2 so that would be (2*2*2)(2*2*2) get it?

Answer 15

uh I don't understand that though ;-;
It says what is the missing expoent needed to make the = sign true.

Answer 16

So putting -5 and -10 would make it -15 right?

Answer 17

let's do it the other way around

if we want to know 3*?=21 we solve it by 21/3=7

so if we want to know (2^-5) [please tell number here] = 2^-15

we do -15/-5 =

to find which exponent we need

Answer 18

no, that would make 50

Answer 19

jeez then XD how can I make it so it's true, by the way, this is 8th work :P

Answer 20

you would get this: \(\Large \frac{ 1 }{ 2^5*2^5*2^5*2^5*2^5*2^5*2^5*2^5*2^5*2^5 }\)

Answer 21

oh actually you have to divide that by one

Answer 22

so you'd get 2^50

Answer 23

you are confusing \(\Large (a^n)^q =a^{n*q} \) with \(\Large a^n*a^q=a^{n+q} \)

Answer 24

note the difference

Answer 25

it's easy to get these mixed up, but they are fundamentally different

Answer 26

so if \(\Large 2^{?*-5} = 2^{-15} \) than what needs to be on the ? for the equation to be right?

Answer 27

@mario0012 do you need any more explanation? i can work it out in detail if you want

Answer 28

Thank you :)