Приведите дроби к общему знаменателю и выполните действвия а)1/2+1/4;б)2/3+1/6;а)1/2+5/7;б)4/5+1/6;а)1/4+5/6;б)3/20+7/25

Приведем дроби к общему знаменателю и выполним деянья:

1) 1/2 + 1/4 = (1 * 2)/(2 * 2) + 1/4 = 2/4 + 1/4 = (2 + 1)/4 = 3/4;

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

3) 1/2 + 5/7 = (1 * 7)/(2 * 7) + (5 * 2)/(7 * 2) = 7/14 + 10/14 = (7 + 10)/14 = 17/14 = 1 3/14;

4) 4/5 + 1/6 = (4 * 6)/(5 * 6) + (1 * 5)/(6 * 5) = 24/30 + 5/30 = (24 + 5)/30 = 29/30;

5) 1/4 + 5/6 = (1 * 3)/(4 * 3) + (5 * 2)/(6 * 2) = 3/12 + 10/12 = (3 + 10)/12 = 13/12 = 1 1/12;

6) 3/20 + 7/25 = (3 * 5)/100 + (7 * 4)/100 = 15/100 + 28/100 = (15 + 28)/100 = 43/100.