Question

решите ,пожалуйста очень срочно
​

Answer 1

$1)$

$4 \frac{1}{5} \div \frac{7}{15} - 3 \frac{2}{5} \times \frac{10}{17} = \frac{21}{5} \times \frac{15}{7} - \frac{17}{5} \times \frac{10}{17} = 9 - 2 = 7$

$7 \frac{1}{5} \times \frac{5}{6} - 4 \frac{1}{3} \div \frac{13}{6} = \frac{36}{5} \times \frac{5}{6} - \frac{13}{3} \times \frac{6}{13} =6 - 2 = 4$

$2)$

$3 - c = 3 - ( - 2) = 3 + 2 = 5$

$4c - 5 = 4 \times ( - 4) - 5 = - 16 - 5 = - 21$

$- 21 < 5$

$3)$

$3a + 6b = 3 \times 10.3 + 6 \times 16.8 = 30.9 + 100.8 = 131.7$

$3a + 6b = 3 \times 9.8 + 6 \times 14.4 = 29.4 + 86.4 = 115.8$