Tính

BÀI 1
a) (-1/6).(-15/19)+(-38/45).9/19
b)-1/24-[1/4-(1/2-7/8)]
c)(3-1/4+2/3)-(5-1/3-6/5)-(6-7/4+3/2)
d)${11}_4^1$-($2_7^5$+$5_4^1$)
e)-1/4.13.9/11-0.25.6.2/11
f)(-1/5+3/7):2/11+(-4/5+4/