Which expression is equivalent to 7^3⋅ 7^-5 as a fraction

When you multiply a base with an exponent by a base with an exponent, you add the exponents together. (But you can only combine the exponents when the bases are the same)

For example:

     (they have the same base of x)

    (you can't combine the exponents because they have different bases of y and x)

When you have a negative exponent, you move the base with the negative exponent to the other side of the fraction to make the exponent positive.

For example:

or

or  

     Add the exponents together

    Make the exponent positive

      Simplify

b. 24 mm

step-by-step explanation:

use the pythagorean theorem.

a^2 + b^2 = c^2

a^2 + 7^2 = 25^2

a^2 + 49 = 625

a^2 = 576

a = 24

answer: b. 24 mm