Реши уравнения с 1 по 20 из задания

Конечно, помогу! 1. $2(5+3x) = 15$ $10 + 6x = 15$ $6x = 15 - 10$ $6x = 5$ $x = \frac{5}{6}$ **Ответ: $x = \frac{5}{6}$** 2. $8 - 5(8+3x) = 13$ $8 - 40 - 15x = 13$ $-15x = 13 - 8 + 40$ $-15x = 45$ $x = \frac{45}{-15}$ $x = -3$ **Ответ: $x = -3$** 3. $2 - 3(7+2x) = 11$ $2 - 21 - 6x = 11$ $-6x = 11 - 2 + 21$ $-6x = 30$ $x = \frac{30}{-6}$ $x = -5$ **Ответ: $x = -5$** 4. $2 - 3(2+3x) = 14$ $2 - 6 - 9x = 14$ $-9x = 14 - 2 + 6$ $-9x = 18$ $x = \frac{18}{-9}$ $x = -2$ **Ответ: $x = -2$** 5. $x - 2(3y+21) = 16$ Недостаточно данных для решения, так как в уравнении две переменные. 6. $3x - 2(3x+4) = 10$ $3x - 6x - 8 = 10$ $-3x = 10 + 8$ $-3x = 18$ $x = \frac{18}{-3}$ $x = -6$ **Ответ: $x = -6$** 7. $2x - 3(3x-1) = 11$ $2x - 9x + 3 = 11$ $-7x = 11 - 3$ $-7x = 8$ $x = -\frac{8}{7}$ **Ответ: $x = -\frac{8}{7}$** 8. $3x - 2(3x-2) = 19$ $3x - 6x + 4 = 19$ $-3x = 19 - 4$ $-3x = 15$ $x = \frac{15}{-3}$ $x = -5$ **Ответ: $x = -5$** 9. $-4x = 15 - 3(3x-5)$ $-4x = 15 - 9x + 15$ $-4x + 9x = 30$ $5x = 30$ $x = \frac{30}{5}$ $x = 6$ **Ответ: $x = 6$** 10. $7x = 13 - 2(8x-7)$ $7x = 13 - 16x + 14$ $7x + 16x = 27$ $23x = 27$ $x = \frac{27}{23}$ **Ответ: $x = \frac{27}{23}$** 11. $-5x = 11 - 2(4x-2)$ $-5x = 11 - 8x + 4$ $-5x + 8x = 15$ $3x = 15$ $x = \frac{15}{3}$ $x = 5$ **Ответ: $x = 5$** 12. $7 - 3(5x-3) = -11x$ $7 - 15x + 9 = -11x$ $-15x + 11x = -7 - 9$ $-4x = -16$ $x = \frac{-16}{-4}$ $x = 4$ **Ответ: $x = 4$** 13. $16 - 7(5-x) = 9$ $16 - 35 + 7x = 9$ $7x = 9 - 16 + 35$ $7x = 28$ $x = \frac{28}{7}$ $x = 4$ **Ответ: $x = 4$** 14. $13 - 6(3-x) = 25$ $13 - 18 + 6x = 25$ $6x = 25 - 13 + 18$ $6x = 30$ $x = \frac{30}{6}$ $x = 5$ **Ответ: $x = 5$** 15. $12 - 8(1-x) = 4$ $12 - 8 + 8x = 4$ $8x = 4 - 12 + 8$ $8x = 0$ $x = 0$ **Ответ: $x = 0$** 16. $5 - 4(7-x) = 11$ $5 - 28 + 4x = 11$ $4x = 11 - 5 + 28$ $4x = 34$ $x = \frac{34}{4} = \frac{17}{2} = 8.5$ **Ответ: $x = 8.5$** 17. $6 - 5(4x-1) = 3$ $6 - 20x + 5 = 3$ $-20x = 3 - 6 - 5$ $-20x = -8$ $x = \frac{-8}{-20} = \frac{2}{5} = 0.4$ **Ответ: $x = 0.4$** 18. $6 - 8 - 5(7x-1)$ $-2 - 35x + 5 = 0$ $-35x + 3 = 0$ $-35x = -3$ $x = \frac{-3}{-35} = \frac{3}{35}$ **Ответ: $x = \frac{3}{35}$** 19. $4 - 7 - 6(5x-1) = 0$ $-3 - 30x + 6 = 0$ $-30x + 3 = 0$ $-30x = -3$ $x = \frac{-3}{-30} = \frac{1}{10} = 0.1$ **Ответ: $x = 0.1$** 20. $5 - 12 - 5(4x-1) = 0$ $-7 - 20x + 5 = 0$ $-20x - 2 = 0$ $-20x = 2$ $x = \frac{2}{-20} = -\frac{1}{10} = -0.1$ **Ответ: $x = -0.1$**