a) (2/3+14/3)×9/40=
16/3×9/40=16×3/40=48/40=12/10=6/5
b)(4/5-2/5)×25/18=
2/5×25/18=5/9
c)14/15×(7/4+27/8×2/9)=
14/15×(7/4+3/4)=
14/15×10/4=28/12=7/3
d)(7/6+3/4×14/9)×15/28=
(7/6+7/6)×15/28=
14/6×15/28= 15/12=5/4
e)(9/7-9/7)×25/18=
0×25/18=0
f) 26/15:(11/9+7/6×8/3)=
26/15:(11/9+28/9)=
26/15:39/9=
26/15×9/39=234/585=78/195=26/65
