if f(x)= x^3 then f(x^5) = x^8

Question

f(x^5) = x^8

f(x) (x^5)/ x^5 = x^8/x^5

f(x)= x^3

 

does my logic hold?

Answer 1

f(x^5) = (x^5)^3 = x^5 * x^5 * x^5 = x^15  

 

Multiplying and dividing by the same thing (x^5) does not change anything.