x . 4 + 15/16 = 1
x . 4 = 1 – 15/16 = 1/16
x = 1/16 : 4 = 1/64
\(\left(x+\frac{1}{2}\right)+\left(x+\frac{1}{4}\right)+\left(x+\frac{1}{8}\right)+\left(x+\frac{1}{16}\right)\)
\(=4x+\left(\frac{8}{16}+\frac{4}{16}+\frac{2}{16}+\frac{1}{16}\right)\)
\(=4x+\frac{15}{16}\)