The sum to infinity of the series is calculated using the formula:
[tex]\begin{gathered} S_n=\frac{a}{1-r} \\ when \\ -1From the series, we have that:[tex]\begin{gathered} a=-2 \\ r=\frac{0.4}{-2}=-0.2 \end{gathered}[/tex]
Since the value of r satisfies the condition, we can apply the formula to get the sum to infinity as shown below:
[tex]\begin{gathered} S_n=\frac{-2}{1-(-0.2)}=-\frac{2}{1.2} \\ S_n=-1.66666666667 \end{gathered}[/tex]
