Solution
= Solution
This <geometric series> has first term one and ratio $-1/4$, whose <absolute value> is less than one. Therefore
$$
\boxed{\sum_{n=0}^{\infty}\left(-\frac14\right)^n=\frac1{1+1/4}=\frac45.}
$$
= Solution
This <geometric series> has first term one and ratio $-1/4$, whose <absolute value> is less than one. Therefore
$$
\boxed{\sum_{n=0}^{\infty}\left(-\frac14\right)^n=\frac1{1+1/4}=\frac45.}
$$