Question

дроби 8 класс алгебра +12б

Answer 1

Ответ:

$\frac{7x}{2(x - 1)} - \frac{5x}{x - 1} =\frac{7x}{2(x - 1)} - \frac{2(5x)}{2(x - 1)} = \frac{7x - 2 \times 5x}{2(x - 1)} = \frac{7x - 10x}{2(x - 1)} = \frac{ - 3x}{2x - 2}$

$\frac{5}{2x - 2} + \frac{3}{4x - 4} = \frac{5}{2(x - 1)} + \frac{3}{4(x - 1)} = \frac{2 \times 5}{2 \times 2(x - 1)} + \frac{3}{4(x - 1)} = \frac{10 + 3}{4(x - 1)} = \frac{13}{4x - 4}$

$\frac{3x}{4x + 4y} - \frac{x}{8x + 8y} = \frac{2 \times 3x}{2(4x + 4y)} - \frac{x}{8x + 8y} = \frac{6x - x}{8x + 8y} = \frac{5x}{8x + 8y}$