a)(15/16:15/4+27/32:27/8)·2-(-6/5+2/9·9/2):(-2/5)=
(15/16·4/15+27/32·8/27)·2-(-6/5+1)·(-5/2)=
(1/4+1/4)·2-(-6+5)/5·(-5/2)=
1/2·2-(-1/5)·(-5/2)=
1-1/2=
1/2
d)(4/10-17/15:8/3+51/20·60/17·5/9)·5=
(2/5-17/5·3/8+5)·5=
(2/5-51/40+5)·5=
(2x8-51+5x40)/40·5=
(16-51+200)/8=
165/8=
20 intregi 5/8
