Question

Thực hiện phép tính:
b) (-99) + (-23) + (-201) + (-17)        c) (-105) - 79 - (-105)
d) (-230) - (-156) - (-230)                  e) (-2021) + (-87) + 2021 + 12

Answer 1

b: \(\left(-99\right)+\left(-23\right)+\left(-201\right)+\left(-17\right)\)

\(=\left(-99-201\right)+\left(-23-17\right)\)

\(=-300-40=-340\)

c: \(\left(-105\right)-79-\left(-105\right)\)

\(=-105-79+105\)

\(=\left(105-105\right)-79\)

=0-79

=-79

d: \(\left(-230\right)-\left(-156\right)-\left(-230\right)\)

\(=-230+156+230\)

\(=\left(-230+230\right)+156\)

=0+156

=156

e: \(\left(-2021\right)+\left(-87\right)+2021+12\)

\(=\left(-2021+2021\right)+\left(-87+12\right)\)

=0+(-75)

=-75