which expression is not equivalent to 1/343

7^4 * 7^-7

7^7 * 7^-10

7^2 * 7^-5

7^-5 * 7^2

i just tried it and got D is this correct ?

correct,

btw, c) and d) are the same answer

oh ok thank you

To find out which expression is not equivalent to 1/343, we need to simplify each expression.

Let's simplify each expression:

1. 7^4 * 7^-7
To simplify this, we can use the rule that says when you multiply two powers with the same base, you add their exponents.
7^4 * 7^-7 = 7^(4 + (-7)) = 7^-3

2. 7^7 * 7^-10
Using the same rule as above, we can simplify this expression.
7^7 * 7^-10 = 7^(7 + (-10)) = 7^-3

3. 7^2 * 7^-5
Again, using the rule for multiplying powers with the same base, we can simplify this expression.
7^2 * 7^-5 = 7^(2 + (-5)) = 7^-3

4. 7^-5 * 7^2
Once more, applying the rule for multiplying powers with the same base, we can simplify this expression.
7^-5 * 7^2 = 7^(-5 + 2) = 7^-3

After simplifying all the expressions, we see that 7^-3 is obtained for each one. Therefore, all expressions are equivalent to 1/343, meaning that none of them is not equivalent to 1/343.