b) 2005 (1+2006) - 2007 × 2004=
=2005 × 2007- 2007 × 2004=
=2007(2005-2004)=
=2007 × 1 = 2007
c) {[(32+42)2 : 53]3 - 23 -33} : 32=
=[( 74 × 2 :53)× 3 -23 - 33] : 32=
=[ ( 148 :35) × 3 -23 - 33] : 32=
=( 148/35 × 3 - 23 - 33) : 32=
=( 444/35 - 805/35 - 1155/35) : 32=
=-1516/35 : 32=
= - 1516/35 × 1/32=
= -379/35 × 1/8=
= -379/280
