\[\boxed{\mathbf{740\ (740)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[\textbf{а)}\ ( - 10) + ( + 11) = + 1\]
\[\textbf{б)}\ ( - 7) + ( - 6) = - 13\]
\[\textbf{в)}\ ( - 12) + ( + 3) = - 9\]
\[\textbf{г)}\ ( - 11) + ( - 20) = - 31\]
\[\textbf{д)}\ ( + 20) + ( - 21) = - 1\]
\[\textbf{е)}\ ( - 100) + ( - 150) = - 250\]