a,
= 51 - 2022 + 2022
= 51
b, = -2019 - 11 + 2019
= -11
c, = 27 - 52 - 37 + 52
= -10
d, = 19 - 32 + 41 - 19 + 25 - 41
= -7
a) (51 - 2022) + 2022
=51+(-2022+2022)
=51+0
=51
b) (-2019) - (11 - 2019)
=(-2019)-11+2019
=(-2019+2019)-11
=0-11
=-11
c) (27 - 52) - (37 - 52)
=27-52-37+52
=[27+(-37)]+(-52+52)
=-10+0
=-10
d) (19 - 32 + 41) - (19 - 25 + 41)
=19-32+41-19+25-41
=(19-19)+(-32-25)+(41-41)
=0+(-57)+0
=-57