Найди значение выражения в задании 3

Задание 3. 1) $10 \cdot (\frac{1}{5})^2 - 12 \frac{1}{5} = 10 \cdot \frac{1}{25} - \frac{61}{5} = \frac{2}{5} - \frac{61}{5} = -\frac{59}{5} = -11.8$ 2) $8 \cdot (\frac{1}{4})^2 - 14 \frac{1}{4} = 8 \cdot \frac{1}{16} - \frac{57}{4} = \frac{1}{2} - \frac{57}{4} = \frac{2}{4} - \frac{57}{4} = -\frac{55}{4} = -13.75$ 3) $21 \cdot (\frac{1}{7})^2 - 10 \frac{1}{7} = 21 \cdot \frac{1}{49} - \frac{71}{7} = \frac{3}{7} - \frac{71}{7} = -\frac{68}{7} = -9.714...$ 4) $6 \cdot (\frac{1}{3})^2 - 17 \frac{1}{3} = 6 \cdot \frac{1}{9} - \frac{52}{3} = \frac{2}{3} - \frac{52}{3} = -\frac{50}{3} = -16.666...$ 5) $18 \cdot (\frac{1}{9})^2 - 20 \frac{1}{9} = 18 \cdot \frac{1}{81} - \frac{181}{9} = \frac{2}{9} - \frac{181}{9} = -\frac{179}{9} = -19.888...$ 6) $15 \cdot (\frac{1}{5})^2 - 8 \frac{1}{5} = 15 \cdot \frac{1}{25} - \frac{41}{5} = \frac{3}{5} - \frac{41}{5} = -\frac{38}{5} = -7.6$ **Ответы:** 1) -11.8 2) -13.75 3) -9.714... 4) -16.666... 5) -19.888... 6) -7.6