The coefficient is what the bariable is multiplied by. In this case, the variable is x and it is multiplied by 4
Since the exponent (-3) is negative, flip the expression to: 1/(5n^4)^3.
Notice how the negative exponent becomes positive as you flip it.
Now evaluate the powers in the denominator: 1/((5^3)(n^4)^3
I separated the constant (5) from the variable (n) to show you how the powers are evaluated.
1/(5x5x5)(nxnxnxn)(nxnxnxn)(nxnxnxn)
—-> the power four means that there are 4 multiples of n in the parentheses. The power 3 corresponds to how many groups.
1/(125)(n^12)
= 1/125n^12
Example
6.
3/8+1/4+__=1
1/4 is the same like 2/8
3/8+2/8=5/8
5/8+__=1
1 is the same like 8/8
5/8+__=8/8
8/8-5/8=_
8/8-5/8=3/8
Blank field-> 3/8