Question

3 уравнения, дам 60 баллов

Answer 1

Ответ:

а)

$- 2.4( - 2x + 0.3) = 1.8(5x - 0.4) - 4.2x \\ 4.8x - 0.72 = 9x - 0.72 - 4.2x \\ 4.8x - 9x + 4.2x = - 0.72 + 0.72 \\ 0x = 0$

х - любое число

б)

$(2x - 3)(6.5 - x) - 10 = 2(x - 3.2) - 2 {x}^{2} \\ 13x - 2 {x}^{2} - 19.5 + 3x - 10 = 2x - 6.4 - 2 {x}^{2} \\ 13x + 3x - 2x = 19.5 - 6.4 + 10 \\ 14x = 23.1 \\ x = 1.65$

в)

$\frac{ - 0.5x}{9} = \frac{ - 0.2(1 + 6x)}{3.6} \: \: \: | \times 3.6 \\ - 0.5x \times 0.4 = - 0.2(1 + 6x) \\ - 0.2x = - 0.2 - 1.2x \\ 1.2x - 0.2x = - 0.2 \\ x = - 0.2$