11/12!МАТЕМАТИКА!СРОЧНО!

Задание 11.

A. $C ( \frac{2 +8}{2} ) = (5)$

Б. $C ( \frac{-2-8}{2} ) = (-5)$

Задание 12.

A. $B _{1} = (- \frac{2}{3} - \frac{1}{3} )= (- \frac{3}{3} ) = (-1)$

$B _{2} = (- \frac{2}{3} + \frac{1}{3} ) = (- \frac{1}{3} )$

Б. $A _{1} =( \frac{1}{3} +3 \frac{5}{6} ) = ( \frac{2}{6} +3 \frac{5}{6} )= (4 \frac{1}{6})$

$A_{2} = ( \frac{1}{3} -3 \frac{5}{6} ) = ( \frac{2}{6} - 3 \frac{5}{6} )= (-3 \frac{3}{6} )=(-3 \frac{1}{2} )$