Sum of the coefficients of(1+x−3x2)171=

Given expansion (1+x−3x2)171 is Sum of the coefficients of (1+x−3x2)171 Let consider f(x)=(1+x−3x2)171   substitute x=1 then we get ⇒f(1)=(1+1−3)171 ⇒f(1)=(−1)171=−1