Question

a) 1+1/3 + 1/9 + 1/27 + 1/81

Answer 1

121/81

Answer 2

\(=\frac{121}{81}\)

Answer 3

\(A=1+\dfrac{1}{3}+\dfrac{1}{9}+\dfrac{1}{27}+\dfrac{1}{81}\) \(\Rightarrow3A=3+1+\dfrac{1}{3}+\dfrac{1}{9}+\dfrac{1}{27}\)

\(\Rightarrow3A-A=3-\dfrac{1}{81}\Rightarrow2A=\dfrac{242}{81}\Rightarrow A=\dfrac{121}{81}\)

Answer 4

=1+(27/81+9/81+3/81+1/81)
=1+40/81
=81/81+40/81
=121/81

Answer 5

121/81