-5a²b+{-3ab²c+ac-[-b²c²+(2abc+b²)]}
= -5a²b+[-3ab²c+ac-(-b²c²+2abc+b²)]
= -5a²b+(-3ab²c+ac+b²c²-2abc-b²)
= -5a²b-3ab²c+ac+b²c²-2abc-b²
因为ab=1 abc=1
= -5a-3b+a+b²-2-b²
= -4a-3b-2
= 3/2+8-2
= 3/2+6
=15/2
-5a²b+{-3ab²c+ac-[-b²c²+(2abc+b²)]}
= -5a²b+[-3ab²c+ac-(-b²c²+2abc+b²)]
= -5a²b+(-3ab²c+ac+b²c²-2abc-b²)
= -5a²b-3ab²c+ac+b²c²-2abc-b²
因为ab=1 abc=1
= -5a-3b+a+b²-2-b²
= -4a-3b-2
= 3/2+8-2
= 3/2+6
=15/2