Помогите пж. 1 и 3 решить

1.

▪а)

$\frac{5}{6} \times 1.04 - \frac{5}{6} \times 0.04 = \frac{5}{6} \times (1.04 - 0.04) = \frac{5}{6} \times 1 = \frac{5}{6}$

▪б)

$18 \times ( - \frac{5}{9} ) - ( - 11) \div ( - 5) = - \frac{18 \times 5}{9} - \frac{11}{5} = - 10 - 2 \frac{1}{5} = - 12 \frac{1}{5}$

3.

$15 + 3x + 6(1 - x) = 2x + 11 \\ 3x - 2x - 6x = 11 - 15 - 6 \\ - 5x = - 10 \: \: \: \: \: | \div - 5 \\ x = 2$