Question

помогите 8 класс Алгебра плииииииззз

Answer 1

$\frac{x}{2y} +\frac{x}{3y} =\frac{3x}{6y} +\frac{2x}{6y}=\frac{5x}{6y}$

$\frac{3}{abc} -\frac{4}{ab}=\frac{3}{abc} -\frac{4c}{abc} =\frac{3-4c}{abc}$

$\frac{2}{m-n} +\frac{3}{m+n}=\frac{2(m+n)}{(m-n)(m+n)}+\frac{3(m-n)}{(m-n)(m+n)} =\frac{2m+2n+3m-3n}{(m-n)(m+n)} = \frac{5m-n}{m^{2}-n^{2}}$

$\frac{1}{x+1} -\frac{1}{x^{2}-1} =\frac{1}{x+1}-\frac{1}{(x-1)(x+1)} =\frac{x-1}{(x-1)(x+1)} -\frac{1}{(x-1)(x+1)} =\frac{x-2}{x^{2}-1}$

$\frac{m}{2n} -\frac{m}{5n}=\frac{5m}{10n}-\frac{2m}{10n} =\frac{3m}{10n}$

$\frac{7}{pq} +\frac{4}{pqt} =\frac{7t}{pqt} +\frac{4}{pqt} =\frac{7t+4}{pqt}$

$\frac{4}{x-y} -\frac{5}{x+y} =\frac{4(x+y)}{(x-y)(x+y)} -\frac{5(x-y)}{(x-y)(x+y)} =\frac{4x+4y-5x+5y}{x^{2}-y^{2}}=\frac{9y-x}{x^{2}-y^{2}}$

$\frac{2}{a^{2}-4} +\frac{1}{a+2} =\frac{2}{(a-2)(a+2)} +\frac{1}{a+2} =\frac{2}{(a-2)(a+2)}+\frac{a-2}{(a-2)(a+2)} =\frac{a}{a^{2}-4}$