3x-15=12. 2y=108+5y. 12,6-b = -5b 4x+8=24. 0,5k=-81-2,5k. 15,3z-3=-3 5x=12+2x. -13=-7x+5....

$3x - 15 = 12 \\ 3x = 27 \\ x = 9$
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$2y = 108 + 5y \\ - 3y = 108 \\ y = - 36$
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$12.6 - b = - 5b \\ 4b = - 12.6 \\ b = - 3.15$
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$4x + 8 = 24 \\ 4x = 16 \\ x = 4$
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$0.5k = - 81 - 2.5k \\ 3k = - 81 \\ k = - 27 \:$
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$15.3z - 3 = - 3 \\ 15.3z = 0 \\ z = 0$
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$5x = 12 + 2x \\ 3x = 12 \\ x = 4$
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$- 13 = - 7x + 5 \\ - 18 = - 7x \\ x = \frac{18}{7} \\ \\ x = 2 \frac{4}{7}$
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$5k + 10.6 = 5k \\ 0 = 10.6 \\ k = 0$
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