793. Решите уравнения: 1) 4x + 5(3 - 2x) = 5 - 11x

Решение уравнений: ### 793. Решите уравнения: 1) $4x + 5(3 - 2x) = 5 - 11x$ $4x + 15 - 10x = 5 - 11x$ $-6x + 15 = 5 - 11x$ $5x = -10$ $x = -2$ 2) $19 - 2(3x + 8) = 2x - 37$ $19 - 6x - 16 = 2x - 37$ $3 - 6x = 2x - 37$ $-8x = -40$ $x = 5$ 3) $8x + 3(7 - 2x) = 4x + 3$ $8x + 21 - 6x = 4x + 3$ $2x + 21 = 4x + 3$ $-2x = -18$ $x = 9$ 4) $23 - 4(3x + 8) = 1 - 17x$ $23 - 12x - 32 = 1 - 17x$ $-12x - 9 = 1 - 17x$ $5x = 10$ $x = 2$ ### 794. Найдите корень уравнений: 1) $\frac{x - 5}{4} = 7 - \frac{2x - 11}{3}$ Умножим на 12: $3(x - 5) = 84 - 4(2x - 11)$ $3x - 15 = 84 - 8x + 44$ $3x + 8x = 128 + 15$ $11x = 143$ $x = 13$ 2) $5 + \frac{7x - 12}{3} = x + 13$ Умножим на 3: $15 + 7x - 12 = 3x + 39$ $7x + 3 = 3x + 39$ $4x = 36$ $x = 9$ 3) $\frac{2 - 7y}{6} + \frac{4y + 7}{3} = -\frac{y}{2}$ Умножим на 6: $(2 - 7y) + 2(4y + 7) = -3y$ $2 - 7y + 8y + 14 = -3y$ $y + 16 = -3y$ $4y = -16$ $y = -4$ 4) $\frac{7y - 1}{12} - \frac{y + 1}{4} = \frac{2y + 5}{3}$ Умножим на 12: $(7y - 1) - 3(y + 1) = 4(2y + 5)$ $7y - 1 - 3y - 3 = 8y + 20$ $4y - 4 = 8y + 20$ $-4y = 24$ $y = -6$ ### 810. Решите уравнения: 1) $\frac{4 - 7x}{15} + \frac{1 - x}{3} = 4 - \frac{2x + 1}{5}$ Умножим на 15: $(4 - 7x) + 5(1 - x) = 60 - 3(2x + 1)$ $4 - 7x + 5 - 5x = 60 - 6x - 3$ $9 - 12x = 57 - 6x$ $-6x = 48$ $x = -8$ 2) $\frac{10 - y}{6} + \frac{3y + 8}{3} = \frac{y + 6}{2}$ Умножим на 6: $(10 - y) + 2(3y + 8) = 3(y + 6)$ $10 - y + 6y + 16 = 3y + 18$ $5y + 26 = 3y + 18$ $2y = -8$ $y = -4$ 3) $\frac{3x + 5}{5} + \frac{9x - 5}{4} = 6 + \frac{3x + 1}{2}$ Умножим на 20: $4(3x + 5) + 5(9x - 5) = 120 + 10(3x + 1)$ $12x + 20 + 45x - 25 = 120 + 30x + 10$ $57x - 5 = 30x + 130$ $27x = 135$ $x = 5$ 4) $\frac{5 - 9x}{8} - \frac{3 + 5x}{4} = \frac{5 - 3x}{2}$ Умножим на 8: $(5 - 9x) - 2(3 + 5x) = 4(5 - 3x)$ $5 - 9x - 6 - 10x = 20 - 12x$ $-19x - 1 = 20 - 12x$ $-7x = 21$ $x = -3$