Answer:
The nonpermissible replacement of the variable n is -4
Step-by-step explanation:
The nonpermissible replacement of the variable in a certain expression is the value of the variable that will make the denominator of the expression zero.
The expression
has the denominator 
This denominator cannot be equal zero, thus,
.
I’m my opinion the best method is elimination
4x + 9 - (10/(3x)) I favored the x^2 then expanded and simplified each rational term