Ответ:
1) - 7 1/2;
2) - 3/10;
3) 1 4/7.
Пошаговое объяснение:
1) 7:(-14/15) = - 7•15/14 = - 1•15/2 = - 7 1/2;
2) - 3/8:5/4 = - 3/8•4/5 = - (3•4)/(8•5) = - (3•1)/(2•5) = - 3/10;
3) -22/21:(-2/3) = + 22/21 • 3/2 = (22•3)/(21•2) = (11•1)/(7•1) = 11/7 = 1 4/7.