8. Раскройте скобки и упростите выражения: a) 9(4-x) + 2(x+5) 6) 4(5k+2)-3(12+2k) в) (4-3x)-7+4(-5x-48)-4 - - д) 8,3(4,3х + 6, 1) – 5, 7(2,8 – 7,4x) e) 9(6x-2)-7+(3+8x) г) -64(7-8)-(4x+37)-(-3) ж) (6x+7)-(6-4x) 2 9. −1 + (+) : 20 - 3

а) 9(4-x) + 2(x+5) = 36 - 9x + 2x + 10 = 46 - 7x

Ответ: 46 - 7x

б) 4(5k+2) - 3(12+2k) = 20k + 8 - 36 - 6k = 14k - 28

Ответ: 14k - 28

в) (4-3x)⋅7 + 4(-5x-48)⋅4 = 28 - 21x - 80x - 768 = -740 - 101x

Ответ: -740 - 101x

г) -64(7-8x) - (4x+37)⋅(-3) = -448 + 512x + 12x + 111 = -337 + 524x

Ответ: -337 + 524x

д) 8.3(4.3x + 6.1) - 5.7(2.8 - 7.4x) = 35.69x + 50.63 - 15.96 + 42.18x = 77.87x + 34.67

Ответ: 77.87x + 34.67

e) 9(6x-2) - 7 + (3+8x) = 54x - 18 - 7 + 3 + 8x = 62x - 22

Ответ: 62x - 22

ж) \(\frac{3}{4}\)(6x+7) - \(\frac{5}{12}\)(6-4x) = \(\frac{18x}{4} + \frac{21}{4}\) - \(\frac{30}{12} + \frac{20x}{12}\) = \(\frac{54x}{12} + \frac{63}{12} - \frac{30}{12} + \frac{20x}{12}\) = \(\frac{74x}{12} + \frac{33}{12}\) = \(\frac{37x}{6} + \frac{11}{4}\)

Ответ: \(\frac{37x}{6} + \(\frac{11}{4}\)

9. -1 + (\(\frac{7}{12}\) + \(\frac{5}{6}\)) : 2\(\frac{5}{6}\) - \(\frac{2}{3}\) = -1 + (\(\frac{7}{12}\) + \(\frac{10}{12}\)) : \(\frac{17}{6}\) - \(\frac{2}{3}\) = -1 + \(\frac{17}{12}\) : \(\frac{17}{6}\) - \(\frac{2}{3}\) = -1 + \(\frac{17}{12}\) * \(\frac{6}{17}\) - \(\frac{2}{3}\) = -1 + \(\frac{1}{2}\) - \(\frac{2}{3}\) = -\(\frac{6}{6}\) + \(\frac{3}{6}\) - \(\frac{4}{6}\) = -\(\frac{7}{6}\) = -1\(\frac{1}{6}\)

Ответ: -1\(\frac{1}{6}\)