Rút gọn các biểu thức sau

b,-2/5x4/15-3/10x4/15
c,(-3/4+2/5):3/7+(3/5-1/4):3/7
d,-11/24:17/23-11/24:17/11-1/12
e,-15/14:17/23-15/14:17/11-6/7
f,(-6/5+2/5):3/8+(4/5-11/30):3/8
g,2/3-2/5+2/10 trên 8/3-8/5+8/10 tất cả+1/2