148 : а,б,в 149 150

### Решение заданий #### №148 а) $2x + 9 = 13 - x$ $2x + x = 13 - 9$ $3x = 4$ $x = 4 / 3 = 1\frac{1}{3}$ б) $14 - y = 19 - 11y$ $-y + 11y = 19 - 14$ $10y = 5$ $y = 5 / 10 = 0,5$ в) $0,5a + 11 = 4 - 3a$ $0,5a + 3a = 4 - 11$ $3,5a = -7$ $a = -7 / 3,5 = -2$ #### №149 а) $3x - 8 = x + 6$ $3x - x = 6 + 8$ $2x = 14$ $x = 7$ б) $7a - 10 = 2 - 4a$ $7a + 4a = 2 + 10$ $11a = 12$ $a = 12/11 = 1\frac{1}{11}$ в) $\frac{1}{6}y - \frac{1}{2} = 3 - \frac{1}{2}y$ $\frac{1}{6}y + \frac{1}{2}y = 3 + \frac{1}{2}$ $\frac{1}{6}y + \frac{3}{6}y = 3,5$ $\frac{4}{6}y = 3,5$ $\frac{2}{3}y = 3,5$ $y = 3,5 \cdot 1,5 = 5,25$ г) $2,6 - 0,2b = 1,1 - 0,5b$ $-0,2b + 0,5b = 1,1 - 2,6$ $0,3b = -1,5$ $b = -1,5 / 0,3 = -5$ д) $p + \frac{1}{4} = \frac{3}{4} + \frac{1}{2}p$ $p - 0,5p = 0,75 - 0,25$ $0,5p = 0,5$ $p = 1$ е) $0,8 - b = 3,2 + b$ $-b - b = 3,2 - 0,8$ $-2b = 2,4$ $b = -1,2$ ж) $\frac{2}{3}x = \frac{1}{3}x$ $\frac{2}{3}x - \frac{1}{3}x = 0$ $\frac{1}{3}x = 0$ $x = 0$ з) $2x - 11 = 0$ $2x = 11$ $x = 5,5$ #### №150 а) $(x + 1) - (x - 1) = 6x$ $x + 1 - x + 1 = 6x$ $2 = 6x$ $x = 2 / 6 = 1/3$ б) $0,3p - 1 = (p + 2) - 1$ $0,3p - 1 = p + 2 - 1$ $0,3p - p = 1 + 1$ $-0,7p = 2$ $p = -20/7 = -2\frac{6}{7}$ в) $6x - (7x - 12) = 101$ $6x - 7x + 12 = 101$ $-x = 101 - 12$ $-x = 89$ $x = -89$ г) $20x - 19 = (8 + 12x)$ $20x - 12x = 8 + 19$ $8x = 27$ $x = 27 / 8 = 3,375$