Реши уравнения: 1) 5x + (3x-7)=9,

Конечно, решим уравнения! **1 уровень** 1) $5x + (3x - 7) = 9$ $5x + 3x - 7 = 9$ $8x = 9 + 7$ $8x = 16$ $x = 2$ 2) $3y - (5 - y) = 11$ $3y - 5 + y = 11$ $4y = 11 + 5$ $4y = 16$ $y = 4$ 3) $48 = 11 - (9a + 2)$ $48 = 11 - 9a - 2$ $48 = 9 - 9a$ $9a = 9 - 48$ $9a = -39$ $a = -\frac{39}{9} = -\frac{13}{3}$ 4) $13 - (5x + 11) = 6x$ $13 - 5x - 11 = 6x$ $2 - 5x = 6x$ $2 = 11x$ $x = \frac{2}{11}$ **2 уровень** 1) $(7x + 1) - (6x + 3) = 5$ $7x + 1 - 6x - 3 = 5$ $x - 2 = 5$ $x = 7$ 2) $(8x + 11) - 13 = 9x - 5$ $8x + 11 - 13 = 9x - 5$ $8x - 2 = 9x - 5$ $3 = x$ $x = 3$ 3) $2 = (3x - 5) - (7 - 4x)$ $2 = 3x - 5 - 7 + 4x$ $2 = 7x - 12$ $14 = 7x$ $x = 2$ 4) $8x + 5 = 119 + (7 - 3x)$ $8x + 5 = 119 + 7 - 3x$ $8x + 5 = 126 - 3x$ $11x = 121$ $x = 11$ **3 уровень** 1) $(5x - 3) + (7x - 4) = 8 - (15 - 11x)$ $5x - 3 + 7x - 4 = 8 - 15 + 11x$ $12x - 7 = -7 + 11x$ $x = 0$ 2) $(4x + 3) - (10x + 11) = 7 + (13 - 4x)$ $4x + 3 - 10x - 11 = 7 + 13 - 4x$ $-6x - 8 = 20 - 4x$ $-2x = 28$ $x = -14$ 3) $(7 - 5x) - (8 - 4x) + (5x + 6) = 8$ $7 - 5x - 8 + 4x + 5x + 6 = 8$ $4x + 5 = 8$ $4x = 3$ $x = \frac{3}{4}$ 4) $(3 - 2x) + (4 - 3x) + (5 - 5x) = 12 + 7x$ $3 - 2x + 4 - 3x + 5 - 5x = 12 + 7x$ $12 - 10x = 12 + 7x$ $-10x = 7x$ $17x = 0$ $x = 0$