Question

(3x+1/x)^3 expand in standard formulae​

Answer 1

Answer:

(3x+ 1/x)^3

[a+b]^3=a^3+b^3+3a^2b+3ab^2

=[3x]^3+[1/x]^3+3*[3x]^2*[1/x]+3*3x*[1/x]^2

=[27x^3]+[1/x^3]+[9x^2/x]+9x/x^2

27x^3+1/x^3+9x+9/x