Question

2 и 3, дам 50 баллов

Answer 1

Пошаговое объяснение:

2.

$0.2(7x - 6y) - 0.3(3x - 4y) = \\ = 1.4x - 1.2y - 0.9x + 1.2y = \\ = 0.5x = \frac{x}{2}$

3.

$0.5(4 + x) - 0.4(x - 3) = 2.5 \\ 2 + 0.5x - 0.4x + 1.2 = 2.5 \\ 0.1x = - 0.7 \\ x = - 7$