1.

The coefficient of xr(0≤r≤(n–1)) in the expansion of (x+3)n−1+(x+3)n−2(x+2)+(x+3)n−3(x+2)2+⋯+(x+2)n−1.

Answer» The coefficient of xr(0r(n1)) in the expansion of (x+3)n1+(x+3)n2(x+2)+(x+3)n3(x+2)2++(x+2)n1.


Discussion

No Comment Found