(2 7/9 z+3 1/3)*3/5 = 1/6 z+6 1/2
(2 7/9 z+3 1/3)*3/5 = 1/6 z+6 1/2 (25/9 z+10/3)*3/5 - 1/6 z= 6 1/2 25*3/9*5 z + 10*3/3*5 -1/6 z= 6 1/2 5/3 z + 2 - 1/6 z= 6 1/2 10/6 z - 1/6 z = 6 1/2 - 2 9/6 z = 4 1/2 3/2 z = 9/2 z= 9/2 : 3/2 z= 9/2 * 2/3 z= 3