oblicz a) (6/7 - 9/14) * 2 1/3 + (7 - 6 7/20) ; 6 1/2 = / = kreska ułamkowa

(6/7 - 9/14) * 2 1/3 + (7 - 6 7/20) : 6 1/2 = (12/14 - 9/14) * 7/3 + (7 - 6 7/20) : 13/2 = 3/14 * 7/3 + 13/20 : 13/2 = 1/2 + 13/20 * 2/13 = 1/2 + 1/10 = 5/10 + 1/10 = 6/10  

(6/7 [to 12/14] -9/14) * 2 1/3 + (7-6 7/20) : 6 1/2 = 3/14 * 2 1/3 + (7-6 7/20 [to 6,35] ) : 6 1/2= 3/14 * 2 1/3 (to 7/3) + 0,65 : 6 1/2 =21/42 (to 1/2) +0,65 : 6 1/2 (to 13/2) =1/2 + 1/10= 5/10 + 1/10 = 6/10 = 0,6