Please answer all or any of the following:-

Using appropriate properties find:
a) (-3/4 ) x 2/3 + 2/7 x ( -14/8) - 5/6 x 3/4
b) (-7/8) x 2/3 – 1/4 x 3/5 + 4/5 x 7/8
c) 3/4 x (-7/2 ) – 1/6 x 3/2 + 5/2 x ¾