72.(28 - 49) + 28.(-49 - 72)
= 72.28 - 72.49 + 28.(-49) - 28.72
= (72.28 - 28.72) - [72.49 - 28.(-49)
= 0 - [(-72)(-49) - 28.(-49)]
= 0 - [(-49).(-72 - 28)]
= 0 - [(-49).(-100)]
= 0 - 4900
= -4900
72.(28-49)+28.(-49-72)=72.28-72.49+28.(-49)-28.72
=72.28-28.72+28.(-49)-(-72).49
=72.28-28.72+28.(-49)-(-49).72
=72.(28-28)+(-49).(28+72)
=0+(-49).100
=-4900
72 . ( 28 - 49 ) + 28 . (-42 - 72)
= 72 . (-21) + (-30)
= 72 . (-51)
= 21
Hk tốt
k nhé
72.(28-49)+28.(-49-72)
=72.28-72.49+28.(-49)-28.72
=(72.28-28.72)-[72.49-28.(-49)
=0-[-72.(-49)-28.(-49)]
=0-[(-49.(-72-28)]
=0-[-49.(-100)]
=0-4900
=-4900