Решите линейные уравнения: 1. а) 3x = 6; б) 1/3x = -5; в) -2x = 12; г) 3/7x = 9...

1. а) $3x = 6 \Rightarrow x = 6 : 3 \Rightarrow x = 2$ б) $\frac{1}{3}x = -5 \Rightarrow x = -5 \cdot 3 \Rightarrow x = -15$ в) $-2x = 12 \Rightarrow x = 12 : (-2) \Rightarrow x = -6$ г) $\frac{3}{7}x = 9 \Rightarrow x = 9 : \frac{3}{7} \Rightarrow x = 9 \cdot \frac{7}{3} \Rightarrow x = 21$ 2. а) $4x + 20 = 0 \Rightarrow 4x = -20 \Rightarrow x = -5$ б) $\frac{3}{2}x - 6 = 0 \Rightarrow \frac{3}{2}x = 6 \Rightarrow x = 6 \cdot \frac{2}{3} \Rightarrow x = 4$ в) $5x - 15 = 0 \Rightarrow 5x = 15 \Rightarrow x = 3$ г) $\frac{2}{5}x + 4 = 0 \Rightarrow \frac{2}{5}x = -4 \Rightarrow x = -4 \cdot \frac{5}{2} \Rightarrow x = -10$ 3. а) $7x + 9 = 100 \Rightarrow 7x = 91 \Rightarrow x = 13$ б) $26x - 0,8 = 7 \Rightarrow 26x = 7,8 \Rightarrow x = 0,3$ в) $\frac{1}{2}x - \frac{1}{3} = \frac{1}{6} \Rightarrow \frac{1}{2}x = \frac{1}{6} + \frac{2}{6} \Rightarrow \frac{1}{2}x = \frac{3}{6} \Rightarrow \frac{1}{2}x = \frac{1}{2} \Rightarrow x = 1$ г) $17,5x - 0,5 = 34,5 \Rightarrow 17,5x = 35 \Rightarrow x = 2$ 4. а) $9 + 13x = 35 + 26x \Rightarrow 13x - 26x = 35 - 9 \Rightarrow -13x = 26 \Rightarrow x = -2$ б) $\frac{7}{9}x + 3 = \frac{2}{3}x + 5 \Rightarrow \frac{7}{9}x - \frac{6}{9}x = 2 \Rightarrow \frac{1}{9}x = 2 \Rightarrow x = 18$ в) $0,81x - 71 = 1,11x + 1 \Rightarrow 0,81x - 1,11x = 1 + 71 \Rightarrow -0,3x = 72 \Rightarrow x = -240$ г) $\frac{1}{3}y - 4 = \frac{1}{4}y - 5 \Rightarrow \frac{4}{12}y - \frac{3}{12}y = -5 + 4 \Rightarrow \frac{1}{12}y = -1 \Rightarrow y = -12$ 5. а) $11x - 4x = 14 \Rightarrow 7x = 14 \Rightarrow x = 2$ б) $20x - 13x - 12x = 6 \Rightarrow -5x = 6 \Rightarrow x = -1,2$ в) $9x + 4x = -26 \Rightarrow 13x = -26 \Rightarrow x = -2$ г) $11x + 7x - 24x = 42 \Rightarrow -6x = 42 \Rightarrow x = -7$ 6. а) $\frac{10}{18}x - \frac{63}{18}x + \frac{17}{18}x = -\frac{1}{4} \Rightarrow -\frac{36}{18}x = -\frac{1}{4} \Rightarrow -2x = -\frac{1}{4} \Rightarrow x = \frac{1}{8} = 0,125$ б) $\frac{1}{6}x - \frac{3}{8}x = 1,37 + 0,82 \Rightarrow \frac{4}{24}x - \frac{9}{24}x = 0,55 \Rightarrow -\frac{5}{24}x = \frac{11}{20} \Rightarrow x = \frac{11}{20} \cdot (-\frac{24}{5}) \Rightarrow x = -\frac{66}{25} = -2,64$ в) $\frac{6}{54}x + \frac{21}{54}x - \frac{22}{54}x = 2,5 \Rightarrow \frac{5}{54}x = \frac{5}{2} \Rightarrow x = \frac{5}{2} \cdot \frac{54}{5} \Rightarrow x = 27$ г) $0,07 - 3\frac{1}{9}x = 0,26 - x \Rightarrow x - 3\frac{1}{9}x = 0,26 - 0,07 \Rightarrow -2\frac{1}{9}x = 0,19 \Rightarrow -\frac{19}{9}x = \frac{19}{100} \Rightarrow x = -\frac{9}{100} = -0,09$