Tính

Bài 1
A) 4/9 - 8/15 + 5/9 - 2/11 - 7/15
b) 5/7 - 3/4 + -1/5 + 2/7 - 1/4

Bài 2"
a) x + -1/8= 3/8
b) -2/9 + 8/15 + x= -7/18
c) x-5/3= -8/3
d 16/9 - x= -7/9
e) x- ( 1 + 3/7) = -8/21
f) -9/4 - x = -5/12 - 7/3
g) -1/2 + x= -2/3