[3/10 - (1/2 - 1/5) * (-5/9)] * (3 - 1/2) + (1/4 - 1/2) = 11/12
3 1 2 5 4 7 6
1. 1/2 - 1/5 = 5/10 - 2/10 = 3/10
2, 3/10*(-5/9) = -3*5 / (5*2*3*3) = - 1/6
3. 3/10 - (-1/6) = 3/10 + 1/6 = 9/30 + 5/30 = 14/30 = 7/15
4. 3 - 1/2 = 6/2 - 1/2 = 5/2
5/ 7/15 * 5/2 = 7/6
6. 1/4 - 1/2 = 1/4 - 2/4 = -1/4
7, 7/6 - 1/4 = 14/12 - 3/12 = 11/12