[tex]4(5x + 9y - z) = 4 \times 5x + 4 \times 9y + 4 \times ( - z) = 20x + 36y - 4z[/tex]

[tex] - 6( - a - 8b + 7c) = - 6 \times ( - a) - 6 \times ( - 8b) - 6 \times 7c = 6a + 48b - 42c[/tex]

[tex](6p - n - 4m) \times ( - 1.6) = - 1.6 \times 6p - 1.6 \times ( - n) - 1.6 \times ( - 4m) = - 9.6p + 1.6n + 6.4m[/tex]

[tex]( - 2.6a - b + 1.4c) \times ( - m) = - m \times ( - 2.6a) - m \times ( - b) - m \times 1.4c = 2.6am + bm - 1.4cm[/tex]

[tex] - 0.7n(7a - 2.1 + 5k) = - 0.7n \times 7a - 0.7n \times ( - 2.1) - 0.7n \times 5k = - 4.9an + 1.47n - 3.5kn[/tex]

[tex] - 24( \frac{7}{12 }x + 0.5y - \frac{5}{6}z - 0.3) = - \frac{24 \times 7}{12} x - \frac{24 \times 1}{2} y + \frac{24 \times 5}{6} z + \frac{24 \times 3}{10} = - 14x - 12y + 20z + 7.2[/tex]