1)1/4+3/10 2)7/25+8/20 3)4/5-1/2 4)17/40-11/200 1)1\4+0,7-1/5 2)

1) 1/4 + 3/10 = 5/20 + 3 * 2/20 = (5 + 3 * 2)/20 =  (5 + 6)/20 = 11/20;

Ответ: 11/20.

2) 7/25 + 8/20 = 7 * 2/50 + 4/10 = 14/50 + 4 * 5/50 = (14 + 4 * 5)/50 = (14 + 20)/50 = 34/50;

Ответ: 34/50.

3) 4/5 - 1/2 = 4 * 2/10 - 5/10 = (8 - 5)/10 = 3/10;

Ответ: 3/10.

4) 17/40 - 11/200 = 17/40 - 11/200 = 17 * 5/200 - 11/200 = 85/200 - 11/200 = (85 - 11)/200 = 74/200 = 37/100;

Ответ: 37/100.

1) 1/4 + 0,7 - 1/5 = 1/4 + 7/10 - 1/5 = 5/20 + 14/20 - 4/20 = (5 + 14 - 4)/20 = 15/20 = 3/4.

Ответ: 3/4.