On comparing, we get −1+A+2B+2C=8....(i) −2+B−3C=−2.....(ii) and 1−A−B+C=−2 .....(iii) On solving we have A=1,B=3 and C=1 ∴ Given expression is
‌
2x3+8x2−2x−2
(1−x)(1+x)(1−2x)
=1−‌
1
1−2x
−‌
3
1−x
+‌
1
1+x
=1−(1−2x)−1−3(1−x)−1+(1+x)−1
∴ Coefficient of x10 is −210−3+1=−2−210=l and constant term is 1−1−3+1=−2=m ∴‌‌lm=4(1+29)