8/11 × 8 1/41 8/13 × 3 5/70,2 × 1 2/3 0,8 × 1/5(0,2+ 0,4)× 2/3​

1) 8/11 * 8 1/4 = 8/11 * 33/4 = 8*33/11*4 = 6

2) 1 8/13 * 3 5/7 = 21/13 * 26/7 = 21*26/13*7 = 6

3) 0.2* 1 2/3 = 1/5 * 5/3 = 1*5/5*3 = 1/3

4) 0.8* 1/5 = 4/5 * 1/5 = 4*1/5*5 = 4/25

5) (0.2+0.4)* 2/3 = 3/5 * 2/3 = 3*2/5*3 = 2/5