Question

Помогите решить уравнения пожалуйста!!! Буду очень благодарен!!!!

Answer 1

а)
$1.5x + 4 = 0.3x - 2 \\ 1.5x - 0.3x = - 2 - 4 \\ 1.2x = - 6 \\ x = \frac{ - 6}{1.2} = - 6 \div \frac{12}{10} = - 6 \times \frac{10}{12} = - 5$
б)
$3(2x - 9) = 4(x - 4) \\ 6x - 27 = 4x - 16 \\ 6x - 4x = - 16 + 27 \\ 2x = 11 \\ x = \frac{11}{2} = 5 \frac{1}{2}$
в)
$7x - (3 + 2x) = x - 9 \\ 7x - 3 - 2x = x - 9 \\ 5x - 3 = x - 9 \\ 5x - x = - 9 + 3 \\ 4x = - 6 \\ x = - \frac{6}{4} = - \frac{3}{2} = - 1.5$
г)
$5 - \frac{x + 7}{6} = \frac{1 0 - 2x}{3} \\ \frac{30}{6} - \frac{x + 7}{6} = \frac{2(1 0 - 2x)}{6} \\ 30 - (x + 7) = 2(10 - 2x) \\ 30 - x - 7 = 20 - 4x \\ - x + 4x = 20 - 30 + 7 \\ 3x = - 3 \\ x = - 1$
д)
$3 - 2.6x = 5x + 1.48 \\ - 2.6x - 5x = 1.48 - 3 \\ - 7.6x = - 1.52 \\ x = \frac{ - 1.52}{ - 7.6} = \frac{152}{100} \div \frac{76}{10} = \frac{152}{100} \times \frac{10}{76} = \frac{2}{10} = 0.2$
е)
$1.6(x + 5) = 4(4.5 - 0.6x) \\ 1.6x + 8 = 18 - 2.4x \\ 1.6x + 2.4x = 18 -8 \\ 4x = 10 \\ x = \frac{10}{4} = 2.5$
ж)
$9x - (6x + 2.5) = - (x - 5.5) \\ 9x - 6x - 2.5 = - x + 5.5 \\ 3x - 2.5 = - x + 5.5 \\ 3x + x = 5.5 + 2.5 \\ 4x = 8 \\ x = 2$
з)
$\frac{3}{8} x - \frac{5}{6} = \frac{7}{12} x - \frac{2}{3} \\ \frac{9x}{24} - \frac{20}{ 24} = \frac{14x}{24} - \frac{16}{24} \\ 9x - 20 = 14x - 16 \\ 9x - 14x = - 16 + 20 \\ - 5x = 4 \\ x = - \frac{4}{5} = - 0.8$
и)
$\frac{7}{20} x + \frac{5}{12} = \frac{2}{3} - \frac{1}{5} x \\ \frac{21x}{60} + \frac{25}{60} = \frac{40}{60} - \frac{12x}{60} \\ 21x + 25 = 40 - 12x \\ 21x + 12x = 40 - 25 \\ 33x = 15 \\ x = \frac{15}{33}$
к)
$\frac{4}{15} + \frac{2}{3} x = x - \frac{7}{10} \\ \frac{8}{30} + \frac{20x}{30} = \frac{30x}{30} - \frac{21}{30} \\ 8 + 20x = 30x - 21 \\ 20x - 30x = - 21 - 8 \\ - 10x = - 29 \\ x = - \frac{29}{10} = - 2.9$