Question

помогите пожалуйста
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Answer 1

Объяснение:

$1)0.9x - 0.6(x - 3) = 2(0.2x - 1.3) \\ 0.9x - 0.6x + 1.8 = 0.4x - 2.6 \\ 0.1x = 4.4 \\ x = 4$

$2) - 0.4(3x - 1) + 8(0.8x - 0.3) = 5 - (3.8x + 4) \\ - 1.2x + 0.4 + 6.4x - 2.4 = 5 - 3.8x - 4 \\ 9x = 3 \\ x = \frac{1}{3}$

$3) \frac{4}{7} (0.56 - 4.2y) + 0.4 = \frac{5}{13} (0.52 - 6.5y) \\ \frac{4 \times 56}{7 \times 100} - \frac{4 \times 42}{7 \times 10} y + 0.4 = \frac{5 \times 52}{13 \times 100} - \frac{5 \times 65}{13 \times 10} y \\ \frac{8}{25} - \frac{12}{5} y + 0.4 = \frac{1}{5} - \frac{5}{2} y \\ 0.32 - 2.4y + 0.4 = 0.2 - 2.5y \\ 0.1y = - 0.52 \\ y = - 5.2$