Find the 7th term in the expansion of (3x2−1x3)10.
Tn=Tr+1=(−1)rxn−ryrx10Cr
n=7,r=6,x=3x2,y=1x3
T7=T6+1=(−1)610C6(3x2)4(1x3)6
=10C634x8×1x18=10C6×81x10=210×81x10
=17010x10