\(52:x=\frac{1}{4}+\frac{1}{28}+\frac{1}{70}+\frac{1}{130}\)
\(52:x=\frac{1}{1\times4}+\frac{1}{4\times7}+\frac{1}{7\times10}+\frac{1}{10\times13}\)
\(52:x=\frac{1}{3}\times\left(\frac{3}{1\times4}+\frac{3}{4\times7}+\frac{3}{7\times10}+\frac{3}{10\times13}\right)\)
\(52:x=\frac{1}{3}\times\left(1-\frac{1}{4}+\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+\frac{1}{10}-\frac{1}{13}\right)\)
\(52:x=\frac{1}{3}\times\left(1-\frac{1}{13}\right)\)
\(52:x=\frac{1}{3}\times\frac{12}{13}\)
\(52:x=\frac{4}{13}\)
\(x=52:\frac{4}{13}\)
\(x=169\)
52 :x =1/4 + 1/28 +1/70 + 1/130
52 : x = 4/13
x = 52 : 4/13
x = 169