Question 12977
Remember, you change a negative exponent into a positive exponent by moving the term with the exponent down into the denominator (if it was in the numerator) or up to the numerator (if it was in the denominator).

Examples:

{{{a^(-2) = 1/a^2}}}

{{{n^3 = 1/n^(-3)}}}

For your problem then:

{{{7^(-4) = 1/7^4}}} and {{{7^4 = 7*7*7*7}}} = 2401

{{{1/7^4 = 1/2401}}}