• Тренин )1,43:1,3-0,2 43 401:80 4)-4,5-6,24:1,6 5) 5,405,5+37 19 15.9 92

Решение:

1) \(\frac{8}{9} \cdot \frac{5}{12} \cdot \frac{8}{15} = \frac{8 \cdot 5 \cdot 8}{9 \cdot 12 \cdot 15} = \frac{320}{1620} = \frac{32}{162} = \frac{16}{81}\) 2) \(1.43 : 1.3 - 0.2 = 1.1 - 0.2 = 0.9\) 3) \((\frac{13}{4} - \frac{11}{40}) : \frac{43}{80} = (\frac{130}{40} - \frac{11}{40}) : \frac{43}{80} = \frac{119}{40} : \frac{43}{80} = \frac{119}{40} \cdot \frac{80}{43} = \frac{119 \cdot 80}{40 \cdot 43} = \frac{119 \cdot 2}{43} = \frac{238}{43} = 5 \frac{23}{43}\) 4) \(-4.5 - 6.24 : 1.6 = -4.5 - 3.9 = -8.4\) 5) \(5.4 - 5.5 + 3.7 = -0.1 + 3.7 = 3.6\) 6) \(\frac{15}{7} + \frac{9}{7} \cdot \frac{2}{3} = \frac{15}{7} + \frac{9 \cdot 2}{7 \cdot 3} = \frac{15}{7} + \frac{18}{21} = \frac{15}{7} + \frac{6}{7} = \frac{21}{7} = 3\)

Ответ: 1) \(\frac{16}{81}\), 2) \(0.9\), 3) \(5 \frac{23}{43}\), 4) \(-8.4\), 5) \(3.6\), 6) \(3\)