Question

Помогите пожалуйста прошу​

Answer 1

$\displaystyle\bf\\1)\\\\\frac{6}{a-b}=\frac{6\cdot b}{(a-b)\cdot b}=\frac{6b}{ab-b^{2} } \\\\\\2)\\\\\frac{a}{x+y} =\frac{a\cdot(x+y)}{(x+y)\cdot(x+y)} =\frac{a\cdot(x+y)}{(x+y)^{2} } =\frac{a\cdot(x+y)}{x^{2} +2xy+y^{2} }\\\\\\3)\\\\\frac{1}{5+m} =\frac{1\cdot(5-m)}{(5+m)\cdot(5-m)} =\frac{5-m}{5^{2} -m^{2} }=\frac{5-m}{25-m^{2} }$