please help! i'll give you a cookie c;

What is the value of the expression 7^-3

A. -21

B. -1/343

C. 1/343

D. 343

Question

please help! i'll give you a cookie c;

What is the value of the expression 7^-3

A. -21

B. -1/343

C. 1/343

D. 343

whpalmer4 · Answer

what is $7^{-3}=$

property of exponents you need to remember:

$$x^{-a} = \frac{1}{x^{a}}$$

and $$\frac{1}{x^{-a}} = x^a$$

whpalmer4 · Answer

I like ginger spice cookies, please :-)

anonymous · Answer

whpalmer4 · Answer

What did you get for the answer?

anonymous · Answer

from what i got, i think the answer is B...?

whpalmer4 · Answer

oh, I'm sorry, I'm not going to be able to share my cookies with you....

whpalmer4 · Answer

compare your problem with my formula:

$$7^{-3}$$$$x^{-a}$$

what is the value of $x$?  What is the value of $a$?

anonymous · Answer

uh.. im not sure.... 
all i did was -7*-7*-7 i dont even know if thats what i was supposed to do but i tried it. (im new to this). but i got -343

whpalmer4 · Answer

just match things up

anonymous · Answer

what do you mean?

whpalmer4 · Answer

you can't tell which number corresponds to x and which corresponds to a here?

$$7^{-3}$$$$x^{-a}$$

anonymous · Answer

oh well, x=7 and a= -3?

whpalmer4 · Answer

no, look more closely

anonymous · Answer

uh

whpalmer4 · Answer

here, I'll make it bigger :-)

$$\large 7^{-3}$$$$\large x^{-a}$$

anonymous · Answer

i dont get it

whpalmer4 · Answer

okay.  you have 3 symbols: 7, -, and 3
you have to match them with 3 other symbols: x, -, and a