Question

plz solve Q10 with explaination

Answer 1

we know 1+w+w^2=0 so 1+w= -w^2.. putting it in given equation we get (-w^2)^7=A+Bw... -w^14=A+Bw.. We also know that w^4=1 it means w^14=w^12×w^2. Therefore w^14=w^2 that's mean -w^2=A+Bw again -w^2=1+w.. so we get 1+w=A+Bw comparing real and imaginary parts and so A=1 & B=1