5/6 = (5*4)/(6*4)=20/24
11/9 = (11*3)/(9*3) = 33/27
2. 4/5 = (4*2)/(5*2) = 8/10
13/25 = (13*4)/(25*4) = 52/100
5/8 = (5*125)/(8*125) = 625/1000
12/125 = (12*8)/(125*8) = 96/1000
133/500 = (133*2)/(500*2) = 266/1000
1) (1/3 - 5/8) * 6/7= (8/24 - 15/24)* 6/7 = -7/24 * 6/7= 1/4
2) ( - 5/12 - 7/30) : 13/15= (- 25/60 - 14/ 60) : 13/15 = -39/60 : 13/15 = 3/4
...=(6*5*3*2*2)/(6*3*27*2*5)=2/27