Реши уравнения: 4.1 a) 3x = 6; б) 1/3 x = -5; в) -2x = 12; г) 3/7 x = 9.

4.1. a) $3x = 6$ $x = 6 / 3$ $x = 2$ 4.1. б) $\frac{1}{3}x = -5$ $x = -5 \cdot 3$ $x = -15$ 4.1. в) $-2x = 12$ $x = 12 / -2$ $x = -6$ 4.1. г) $\frac{3}{7}x = 9$ $x = 9 \cdot \frac{7}{3}$ $x = \frac{63}{3}$ $x = 21$ 4.2. a) $4x + 20 = 0$ $4x = -20$ $x = -20 / 4$ $x = -5$ 4.2. б) $\frac{3}{2}x - 6 = 0$ $\frac{3}{2}x = 6$ $x = 6 \cdot \frac{2}{3}$ $x = \frac{12}{3}$ $x = 4$ 4.3. a) $7x + 9 = 100$ $7x = 100 - 9$ $7x = 91$ $x = 91 / 7$ $x = 13$ 4.3. б) $26x - 0,8 = 7$ $26x = 7 + 0,8$ $26x = 7,8$ $x = 7,8 / 26$ $x = 0,3$ 4.4. a) $9 + 13x = 35 + 26x$ $13x - 26x = 35 - 9$ $-13x = 26$ $x = 26 / -13$ $x = -2$ 4.4. б) $\frac{7}{9}x + 3 = \frac{2}{3}x + 5$ $\frac{7}{9}x - \frac{2}{3}x = 5 - 3$ $\frac{7}{9}x - \frac{6}{9}x = 2$ $\frac{1}{9}x = 2$ $x = 2 \cdot 9$ $x = 18$ 4.5. a) $11x - 4x = 14$ $7x = 14$ $x = 14 / 7$ $x = 2$ 4.5. б) $20x - 13x - 12x = 6$ $20x - 25x = 6$ $-5x = 6$ $x = 6 / -5$ $x = -1,2$ 4.6. a) $\frac{5}{9}x - \frac{7}{4}x + \frac{17}{18}x = -\frac{1}{4}$ $\frac{10}{18}x - \frac{63}{36}x + \frac{34}{36}x = -\frac{9}{36}$ $\frac{20}{36}x - \frac{63}{36}x + \frac{34}{36}x = -\frac{9}{36}$ $\frac{-9}{36}x = -\frac{9}{36}$ $x = -\frac{9}{36} / -\frac{9}{36}$ $x = 1$ 4.6. б) $\frac{1}{6}x - 0,82 = \frac{3}{8}x - 1,37$ $\frac{1}{6}x - \frac{3}{8}x = -1,37 + 0,82$ $\frac{4}{24}x - \frac{9}{24}x = -0,55$ $\frac{-5}{24}x = -0,55$ $x = -0,55 / \frac{-5}{24}$ $x = -0,55 \cdot \frac{-24}{5}$ $x = 2,64$ 4.6. г) $0,07 - 3\frac{1}{9}x = 0,26 - x$ $0,07 - \frac{28}{9}x = 0,26 - x$ $- \frac{28}{9}x + x = 0,26 - 0,07$ $- \frac{28}{9}x + \frac{9}{9}x = 0,19$ $\frac{-19}{9}x = 0,19$ $x = 0,19 / \frac{-19}{9}$ $x = 0,19 \cdot \frac{-9}{19}$ $x = -0,09$