(-7264)+(1543+7264)
=-7264+1543+7264
=(-7264+7264)+1543
=0+1543=1543
(435-167-89)-(435-89)
=435-167-89-435+89
=(435-435)+(-89+89)+(-167)
=0+0+(-167)=-167
(-7264)+(1543+7264)
=(-7264)+1543+7264
=(-7264+7264)+1543
=0+1543
=1542
(435-167-89)-(435-89)
=435-167-89-435+89
=(435-435)+(-89+89)-167
=0+0-167
-167