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