Решите понятно 3 1/5: (z-1/2)=2 2/3: (z+1/3)

2 2/3 * ( z - 1/2 ) = 3 1/5 * ( z + 1/3)
8/3 *( z - 1/2 ) = 16/5 * ( z + 1/3)
8/3z - 8/6 = 16/5z + 16/15
8/3z - 16/5z = 16/15 + 8/6
40/15z - 48/15z = 16/15 + 20/15
-8/15z = 36/15
z = -36/15 * 15/8
z = -4,5