[tex] \frac{5}{10} + \frac{5}{15} + \frac{5}{20} + \frac{5}{25} = \\ \\ \frac{5}{10} + \frac{5}{15} = \frac{5 \times 3}{10 \times 3} + \frac{5 \times 2}{15 \times 2} = \frac{15}{30} + \frac{10}{30} = \frac{15 + 10}{30} = { \frac{25}{30} }^{(5} = \frac{5}{6} \\ \\ \frac{5}{6} + \frac{5}{20} = \frac{5 \times 10}{6 \times 10} + \frac{5 \times 3}{20 \times 3} = \frac{50}{60} + \frac{15}{60} = \frac{50 + 15}{60} = { \frac{65}{60} }^{(5} = \frac{13}{12} \\ \\ \frac{13}{12} + \frac{5}{25} = \frac{13 \times 25}{12 \times 25} + \frac{5 \times 12}{25 \times 12} = \frac{325}{300} + \frac{60}{300} = \frac{325 + 60}{300} = { \frac{385}{300} }^{(5} = \frac{77}{60} = 1 \frac{17}{60} [/tex]
