c)5-197-2015-2015
=(5-197)-(2015+2015)
=-192-4030
=-4222
d) sữa đề :4567+1234-4567-(-66)
=(4567-4567)+1234-(-66)
=1234-(-66)
=1300
e)2004-15+54-2004-54
=(2004-2004)-15+(54+(-54))
=-15
f)-45789-357-45789+57
=(-45789-45789)+(-357+57)
=-91578+(-300)
=-91878