Verified answer

[tex]1) - 4x - 8(9 - 2x) + 12 = - 4x - 72 + 16x + 12 = 12x - 60[/tex]

[tex]2)3(12 - 2.1x) + 0.3x = 36 - 6.3x + 0.3x = 36 - 6x[/tex]

[tex]3)6(3x - 2) + 4(5x - 1) = 18x - 12 + 20x - 4 = 38x - 16[/tex]

[tex]4) - 7(3 - 4x) + 14(0.5 + 2x) = - 21 + 28x + 7 + 28x = 56x - 14[/tex]

[tex]5)3(2.1x - y) - 2.8(2x - 3y) = 6.3x - 3y - 5.6x + 8.4y = 0.7x + 5.4y[/tex]

[tex]6)0.4(8x + 7) - 1.6(2x - 3) = 3.2x + 2.8 - 3.2x + 4.8 = 7.6[/tex]