(z−2√z)9
The general term is
(9Cr)(z)(9−r)(−2√z)r
=(9Cr)(z9zr)((−2)r(√z)r)
=(9Cr)(z9∗(−2)rzr∗(√z)r)
=(9Cr)(z18/2∗(−2)rz(2r/2)∗(z)(r/2))
=(9Cr)(z((18−2r−r)/2)∗(−2)r1)
=(9Cr)(z((18−3r)/2)∗(−2)r)
The constant term will be when
(18−3r)/2=0
18−3r=0
r=6
Just wanna try. This code is really crazy! Typing it twice takes me 30minutes. (I accidentally deleted when I have already finished)