387×(52+49)-387
387×101-387
39087-387
38700
1368+216×10+576+2088
1368+2160+576-2088
3528+576-2088
4104-2088
2016
a/ 52.378+49.378-378
= 378 . (52+49 -1)
= 378 .100
= 37800
b/ 72 .19+36 .6.10+144 /40 -72.29
= 72 . 19 + 216 .10+576 .10 -72.29
= 72 .(19-29) +(216+576).10
= -72 .10 +792 .10
=720.10
= 7200
Dấu . là thay cho dấu \(\times\)đó nha bạn!
a, =52 x 378 + 49 x 378 +378 x 1
=378 x (52 + 49 - 1)
= 378 x 100
=37800
