a) 4(2 - 6) - 3(2 - 3) = 8; б) -6(6 - x) - 5x = 18; в) 1/5(5x - 10) - 2/9(9x - 27) = 9; г) 4,2(3z - 5) - 1,4(5z - 3) = 5,6.

Решение:

1. а)\[ 4(2z - 6) - 3(2z - 3) = 8 \]\[ 8z - 24 - 6z + 9 = 8 \]\[ 2z - 15 = 8 \]\[ 2z = 23 \]\[ z = 11.5 \]
2. б)\[ -6(6 - x) - 5x = 18 \]\[ -36 + 6x - 5x = 18 \]\[ x - 36 = 18 \]\[ x = 54 \]
3. в)\[ \frac{1}{5}(5x - 10) - \frac{2}{9}(9x - 27) = 9 \]\[ x - 2 - 2x + 6 = 9 \]\[ -x + 4 = 9 \]\[ -x = 5 \]\[ x = -5 \]
4. г)\[ 4.2(3z - 5) - 1.4(5z - 3) = 5.6 \]\[ 12.6z - 21 - 7z + 4.2 = 5.6 \]\[ 5.6z - 16.8 = 5.6 \]\[ 5.6z = 22.4 \]\[ z = 4 \]

Ответ: а) z = 11,5; б) x = 54; в) x = -5; г) z = 4.