Вычислите: 1)2/3*(3/4+5/8)=? 2)2-5/6:8/9=? 3)2/3:(3/4-5/12)=? 4)3-2/3*6/7=? 5)3/5*(4/21+2/7)=? 6)3-1/10:2/15=? 7)5/6:(3/4-1/12)=?

1) 2/3 * (3/4 + 5/8) = 2/3 * (6/8 + 5/8) = 2/3 * 11/8 = 11/12.

2) 2 - 5/6 : 8/9 = 2 - 5/6 * 9/8 = 2 - 15/16 = 1 1/16.

3) 2/3 : (3/4 -  5/12) = 2/3 : (9/12 - 5/12) = 2/3 : 4/12 = 2/3 * 3 = 2.

4) 3 - 2/3 * 6/7 = 3 - 4/7 = 2 3/7.

5) 3/5 * (4/21 + 2/7) = 3/5 * (4/21 + 6/21) = 3/5 * 10/21 = 2/7.

6) 3 - 1/10 : 2/15 = 3 - 1/10 * 15/2 = 3 -  3/2 = 3 - 1 1/2 = 1 1/2.

7) 5/6 : (3/4 - 1/12) = 5/6 : (9/12 - 1/12) = 5/6 : 8/12 = 5/6 : 2/3 = 5/6 * 3/2 = 5/4 = 1 1/4.

8) 2 - 3/8 * 4/5 = 2 - 3/10 = 1 7/10.