Bài 2
a.(-53)+(-86)+/+47/+/-86/
=-53-86+47+86
=(-53+47)-(86-86)
=-6-0
=-6
b.42.(58-11)-58.(11+42)
=42.58-42.11-58.11-58.42
=(42.58-58.11-58.42)-42.11
=58.(42-11-42)-42.11
=58.(-11)-42.11
=11.(-58-42)
=11.(-100)
=-1100
c.(-4)³:4²+(-3)².3²-$2019^{0}$
=(-4)+31-1
=26.