Pls help

(2x^3y)^6 = 2^6.x^18.y^6

((2x)^3y)^6 = 2^18.x^18.y^6

2(x^3y)^6 = 2.x^18.y^6

I think this is your actual question.......

Alan is telling you the question that your friend has effectively answered, which is a different question.  Some confusion here. :)

Anyway....

$(2x^3y)^6\\ =(2\times x^3\times y)^6\\ =2^6\times(x^3)^6\times y^6\\ =64\times x^{18}\times y^6\\ =64 x^{18} y^6\\ $