Obtain the first four term in the expansion of (2x-3y)*15

Answer 1

i need an answer

Answer 2

They are, of course,
(2x)^15 + C(15,1) (2x)^14 (-3y) + C(15,2) (2x)^13 (-3y)^2 + C(15,3) (2x)^12 (-3y)^3