(-4/9)+(+4/5)-(+5/6)-(+9/10)-(-1又5/18)
=-4/9+4/5-5/6-9/10+23/18
=(23/18-4/9-5/6)+(4/5-9/10)
=(23-4*2-5*3)/18+(4*2-9)/10
=-1/10
(-4/9)+(+4/5)-(+5/6)-(+9/10)-(-1又5/18)
=-4/9+4/5-5/6-9/10+23/18
=(23/18-4/9-5/6)+(4/5-9/10)
=(23-4*2-5*3)/18+(4*2-9)/10
=-1/10