If `(1+x-2x^2)^6=1+a_1x+a_2x^(12)++a_(12)x^(12),` then find the value of `a_2+a_4+a_6++a_(12)dot`

(1+x-2x^(2))^(6)=1+a_(1)x+a_(2)x^(2)+a_(2)x^(3)+....., then the value of a_(2)+a_(4)+a_(6)+......+a_(12) will be (a) 32 (b) 31 (c) 64 (d) 1024

If (1 + x + x^(2) + x^(3))^(n)= a_(0) + a_(1)x + a_(2)x^(2) + a_(3) x^(3) +...+ a_(3n) x^(3n) , then the value of a_(0) + a_(4) +a_(8) + a_(12)+….. is

If (1+2x^(2))^(6)=1+a_(1)=a_(2)x^(2)a_(3)x^(3)+...+a_(12)x^(12) then the value of expression a_(2)+a_(4)+a_(6)+...+a_(12) is 322.313.634.64