Question

Помогите пожалуйста срочно

Answer 1

Ответ:

1)а.$\frac{3x^{2} }{15x^{3} } =\frac{3x^{2} }{3x^{2}(5x)} =\frac{1}{5x}$

б.$\frac{2x+6}{3x+9} =\frac{2(x+3)}{3(x+3)} =\frac{2}{3}$

в.$\frac{x^{2}-9 }{(x+3)^{2} } =\frac{(x+3)(x-3)}{(x+3)^{2} } =\frac{x-3}{x+3}$

2)$\left \{ {{3x+5y=12} \atop {x-2y=7}} \right. \\\left \{ {{3x+3y=12} \atop {x=7}} \right. \\\left \{ {{21+3y=12} \atop {3y=-9}} \right. \\\left \{ {{y=-3} \atop } \right.$