20-18,6:(6[tex] \frac{11}{15} [/tex] - 4[tex] \frac{3}{20} [/tex])

20 - 18,6 : (6 11/15 - 4 3/20) = 12,81) 6 11/15 - 4 3/20 = 6 44/60 - 4 9/60 = 2 35/60 = 2 7/122) 18,6 : 2 7/12 = 186/10 : 31/12 = 186/10 * 12/31 = (6*6)/(5*1) = 36/5 = 7 1/53) 20 - 7 1/5 = 19 5/5 - 7 1/5 = 12 4/5 = 12,8