357.
в) (3/8 - х) - 1/5 = 1/20.
3/8 - х = 1/20 + 1/5;
3/8 - x = 1/4;
- x = 1/4 - 3/8;
- x = - 1/8;
x = 1/8.
г) 19/20 - x = 1/4.
- х = 1/4 - 19/20;
- x = - 14/20;
x = 7/10.
д) 1/12 + х = 3/4 + 1/6.
х = 3/4 + 1/6 - 1/12;
x = 5/6.
е) 2/3 - (5/6 - х) = 1/12.
2/3 - 5/6 + x = 1/12;
x = 1/12 - 2/3 + 5/6;
x = 1/4.
358.
Пусть х - страниц рассказа, тогда:
16 стр - 2/5 (1 - 3/5)
х стр - 1.
х = 16 : 2/5 = 16 * 5/2 = 40 (стр).