Medium Practice — Set 1

Quick Recap — General Term & Term Independent of $x$

• $T_{r+1}={}^nC_r a^{n-r}b^r$; set the power of $x$ to the required value and solve for $r$.
• Term independent of $x$: power of $x$ equals $0$.
• Coefficient of $x^k$ in $(1+bx)^n$ is $^nC_k\,b^k$.
• Middle term of $(1+x)^{2m}$ is $^{2m}C_m x^m$.