Question

Срочноооооо, алгебра!!!!!!!

Answer 1

Ответ:

7/27

Объяснение на листке

Answer 2

$\frac{1}{a} = \frac{1}{3} -\frac{1}{b} \\\frac{1}{3} -\frac{1}{b} + \frac{1}{c} = \frac{1}{9} \\\frac{1}{c}-\frac{1}{b} = -\frac{2}{9} \\\frac{1}{b} + \frac{1}{b}-\frac{2}{9} = \frac{2}{27}\\ \frac{2}{b} = \frac{8}{27}\\ \frac{1}{b} = \frac{4}{27}\\\frac{1}{a} = \frac{1}{3} -\frac{4}{27} = \frac{5}{27}\\\frac{1}{c} = -\frac{2}{9} + \frac{1}{b} = -\frac{2}{9} + \frac{4}{27}=-\frac{2}{27}\\\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=\frac{5}{27}+\frac{4}{27}-\frac{2}{27}=\frac{12}{27}$

Ответ: $\frac{12}{27}$