Question

Решите плиз
zzzzzzzzzzzzzzzzzzzzz

Answer 1

$-\frac{1}{3}+(-\frac{1}{3})^2+(-\frac{1}{3})^3= -\frac{1}{3} +\frac{1}{9} -\frac{1}{27}= -\frac{1*9}{27} +\frac{1*3}{27} -\frac{1}{27} =-\frac{9}{27}+\frac{3}{27}-\frac{1}{27}= -\frac{7}{27}$

Ответ: $-\frac{7}{27}$