On the chance you are trying to say: Take the return value of the function and then make that equal to itself divide by n, e.g., functionWithArgs(1,2) /= 3, that would not work for multiple reasons as your function has no return value (it will return undefined ) so the outcome of that process would return NaN or it would if you first assigned a variable to the return value of the function, but in this case it throw an error as you cannot reassign undefined
console.log(undefined /= 3 === NaN) // throws an error
//(It does not throw an error in my browser console,
//but it really should, and it will in the FCC console)