1)

[tex] - 7(2 - 3x) = 56 \\ - 14 + 21x = 56 \\ 21x = 70 \\ x = \frac{70}{21} = 3 \frac{7}{21} = 3 \frac{1}{3} [/tex]

2)

[tex]0.8(4x + 5) = - 3.2 \\ 3.2x + 4 = - 3.2 \\ 3.2x = - 7.2 \\ x = 2.25[/tex]

3)

[tex] - 2.4(7 - 9y) = - 48 \\ - 16.8 + 21.6y = - 48 \\ 21.6y = - 31.2 \\ y = - \frac{312}{216} = - 1 \frac{96}{216} = - 1 \frac{4}{9} [/tex]

4)

[tex](5 + 7a) \times 15 = 12 \\ 75 + 105a = 12 \\ 105a = - 63 \\ a = - \frac{63}{105} = - \frac{3}{5} = - 0.6[/tex]

5)

[tex]0.6(2x + 1) = - 1.8(3x - 4) \\ 1.2x + 0.6 = - 5.4x + 7.2 \\ 6.6x = 6.6 \\ x = 1[/tex]

6)

[tex] - 1.4(x - 6) = 7(4x + 1.2) \\ - 1.4x + 8.4 = 28x + 8.4 \\ 26.6x = 0 \\ x = 0[/tex]

7)

[tex] - 40.5(6x + 1) = - 45(2x + 2.6) \\ - 243x - 40.5 = - 90x - 117 \\ - 153x = - 76.5 \\ x = 0.5[/tex]

8)

[tex]2.6(0.4x - 1.4) = - 3.9(1.2x - 0.9) \\ 1.04x - 3.64 = - 4.68x + 3.51 \\ 5.72x = 7.15 \\ x = 1.25[/tex]