tolong di jawab pake langkah langkahnya

a. [tex]r=\frac{u_{2}}{\frac_{1}}=\frac{8}{16}=\frac{1}{2}[/tex]
[tex]u__{n}=ar^{n-1}[/tex]
[tex]\frac{1}{16}=16*(\frac{1}{2})^{n-1}[/tex]
[tex]2^{-4}=2^{4}*2^{-(n-1)}[/tex]
[tex]2^{-4}=2^{4-(n-1)}[/tex]
[tex]-4=4-(n-1)[/tex]
[tex]n-1=8[/tex]
[tex]n=9[/tex]
maka suku tengahnya adalah [tex]\frac{n+1}{2}=\frac{9+1}{2}=5[/tex]
[tex]u_{5}=ar^{4}=16*(\frac{1}{2})^{4}=\frac{16}{16}=1[/tex]

b. [tex]r=\frac{u_{2}}{u_{1}}=\frac{512}{1024}=\frac{1}{2}[/tex]
[tex]u_{n}=ar^{n-1}[/tex]
[tex]4=1024*(\frac{1}{2})^{n-1}[/tex]
[tex]\frac{1}{256}=(\frac{1}{2})^{n-1}[/tex]
[tex](\frac{1}{2})^{8}=(\frac{1}{2})^{n-1}[/tex]
[tex]n-1=8[/tex]
[tex]n=9[/tex]
[tex]u_{5}=ar^{4}=1024*(\frac{1}{2})^{4}=64[/tex]

c. [tex]r=\frac{u_{2}}{u_{1}}=\frac{\sqrt{10}}{\sqrt{5}}=\sqrt{2}[/tex]
[tex]16\sqrt{5}=\sqrt{5}*(\sqrt{2})^{n-1}[/tex]
[tex]2^{4}=2^{\frac{n-1}{2}}[/tex]
[tex]\frac{n-1}{2}=4[/tex]
[tex]n=9[/tex]
[tex]u_{5}=ar^{4}=\sqrt{5}(\sqrt{2})^{4}=4\sqrt{5}[/tex]

d. [tex]r=\frac{u_{2}}{u_{1}}=\frac{-3}{1}=-3[/tex]
[tex]729=1*(-3)^{n-1}[/tex]
[tex](-3)^{6}=(-3)^{n-1}[/tex]
[tex]n-1=6[/tex]
[tex]n=7[/tex]
[tex]u_{4}=ar^{-3}=1*(-3)^{3}=-27[/tex]