(1/30+1/19×(2/3+0,6)):0,01

(1/30 + 1/19 ( 2/3 +6/10)):0,01
(1/30 + 1/19 ( 20/30 +18/30)):0,01 pe prima o amplificam cu 10 iar pe cea de-a doua cu 3
(1/30 + 1/19 x 38/30):0,01
(1/30 + 38/570):0,01 pe prima o amplificam cu 19
(19/570 + 38/570):0,01
57/570 : 0,01
1/10 : 0,01=1/10:1/100=1/10·100/1=10

   [1/30 +1/19 x (2/3 + 0,6)]:0,01 =
= [1/30+1/19 x (2/3 + 6/10)]:1/100 = 
= [1/30 + 1/19 x (2/3+3/5)] : 1/100 = 
= [1/30 + 1/19 x (10/15 + 9/15)] : 1/100 = 
= (1/30 + 1/19 x 19/15) : 1/100 = 
= (1/30 + 1/15) : 1/100 = 
= (1/30 + 2/30) : 1/100 =
= 3/30 : 1/100 = 
= 1/10 : 1/100 = 
= 1/10 x 100/1 = 
= 10