Решите уравнения: 10x-3=2x+21; x+7=5x+27; 13a+2=10a+5; 7b+4=5b-6; 4m-3=-10m-13; 5y-31=2y-40; 3x+10=-3x+2; 3*(x+8)=10x-10; -(3x-4)=2x+8; 10x+13-5x=4x+8-2x; 0,3x-2=-0,7x+8; 1/5a+4=-4/5a+12

1. $10x - 3 = 2x + 21$ $10x - 2x = 21 + 3$ $8x = 24$ $x = 3$ **Ответ: 3** 2. $x + 7 = 5x + 27$ $x - 5x = 27 - 7$ $-4x = 20$ $x = -5$ **Ответ: -5** 3. $13a + 2 = 10a + 5$ $13a - 10a = 5 - 2$ $3a = 3$ $a = 1$ **Ответ: 1** 4. $7b + 4 = 5b - 6$ $7b - 5b = -6 - 4$ $2b = -10$ $b = -5$ **Ответ: -5** 5. $4m - 3 = -10m - 13$ $4m + 10m = -13 + 3$ $14m = -10$ $m = -\frac{10}{14} = -\frac{5}{7}$ **Ответ: -5/7** 6. $5y - 31 = 2y - 40$ $5y - 2y = -40 + 31$ $3y = -9$ $y = -3$ **Ответ: -3** 7. $3x + 10 = -3x + 2$ $3x + 3x = 2 - 10$ $6x = -8$ $x = -\frac{8}{6} = -1\frac{1}{3}$ **Ответ: -1 1/3** 8. $3 \cdot (x + 8) = 10x - 10$ $3x + 24 = 10x - 10$ $3x - 10x = -10 - 24$ $-7x = -34$ $x = \frac{34}{7} = 4\frac{6}{7}$ **Ответ: 4 6/7** 9. $-(3x - 4) = 2x + 8$ $-3x + 4 = 2x + 8$ $-3x - 2x = 8 - 4$ $-5x = 4$ $x = -0,8$ **Ответ: -0,8** 10. $10x + 13 - 5x = 4x + 8 - 2x$ $5x + 13 = 2x + 8$ $5x - 2x = 8 - 13$ $3x = -5$ $x = -1\frac{2}{3}$ **Ответ: -1 2/3** 11. $0,3x - 2 = -0,7x + 8$ $0,3x + 0,7x = 8 + 2$ $1x = 10$ $x = 10$ **Ответ: 10** 12. $\frac{1}{5}a + 4 = -\frac{4}{5}a + 12$ $\frac{1}{5}a + \frac{4}{5}a = 12 - 4$ $1a = 8$ $a = 8$ **Ответ: 8**