a)-(2789-435)+(1789-1435)
=-2789+435+1789-1435
=(-2789+1789)+(435-1435)
=-1000+(-1000)
=-2000
b) -(-2020)+36.41-36.(-59)+(-2020)
=2020+36.41+36.59-2020
=(2020-2020)+36.(41+59)
=0+36.100
=3600
c) -75.(18-65)-65.(75-18)
=-75.18-(-75).65-65.75-(-65).18
=[-75.18-(-75).65-65.75]-(-65).18
=[-75.18-(-75).65+65.(-75)]-(-65).18
=[-75.(18-65+65)]-(-65).18
=-75.18-(-65).18
=18.[-75-(-65)]
=18.(-10)
=-180
d)(157.57-99.57-57^2):57+57
=(157.57-99.57-57.57):57+57
=[57.(157-99-57)]:57+57
=57.1:57+57
=57:57+57
=1+57
=58
CHÚC BẠN HỌC TỐT!