Explicație pas cu pas:
13.a)
[tex]\frac{101}{303} = \frac{101}{3 \cdot 101} = \bf \frac{1}{3} \\ [/tex]
b)
[tex]\frac{121121}{110110} = \frac{121 \cdot 1001}{110 \cdot 1001} = \frac{121}{110} = \frac{{11}^{2}}{10 \cdot 11} = \bf \frac{11}{10} \\ [/tex]
c)
[tex]\frac{126126126}{147147147} = \frac{126 \cdot 1001001}{147 \cdot 1001001} = \frac{126}{147} = \frac{2 \cdot {3}^{2} \cdot 7}{3 \cdot {7}^{2} } = \bf \frac{6}{7} \\ [/tex]