Prove the there is no term containing x10 in the expansion of (x2−2x)18
The general term in the given expansion is given by Tr+1=(−1)r×18Cr×(x2)18−r×(2x)r⇒Tr+1=(−1)r×18Cr×2r×x(36−3r)Let Tr+1 Contain x10 then,36−3r=10⇒3r=26⇒r=263