28 + 72 =
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 )
= -72 .49 + 28 . ( -49)
= 72 . ( -49) + 28 . (-49)
= (72+28) .(-49)
= 100 . (-49)
= -4900
k mình nha !
Tính nhanh:
28*47+28*43+72*29+72*61
28 x 47 + 28 x 43 + 72 x 29 + 72 x 61
= 28 x ( 47 + 43 ) + 72 x ( 29 + 61)
= 28 x 90 + 72 x 90
= 90 x ( 28 + 72)
= 90 x 100
= 9 000
k mk nha
28 x 47 + 28 x 43 + 72 x 29 + 72 x 61
= 28 x (47 + 43) + 72 x (29 + 61)
= 28 x 90 + 72 x 90
= (28 + 72) x 90
= 100 x 90 = 9000
28 x 47 + 28 x 43 + 72 x 29 + 72x 61
= 28( 47 + 43 ) + 72 x ( 61+ 29)
=28 x 90 + 72 x 90
= 90 x (28 + 72 )
= 90 x 100 = 9000
tìm x : ( 72 × 72 + 72× 28 ) + x : 8
\(\left(72.72+72.28\right)+x:8\)
\(\left[72.\left(72+28\right)\right]+x:8\)
\(\left(72.100\right)+x:8\)
\(7200+x:8\)
\(x:8=-7200\)
\(x=-57600\)
vậy \(x=-57600\)
a. \(\frac{4}{25}\times72+\frac{4}{25}\times28=\frac{4}{25}\times\left(72+28\right)=\frac{4}{25}\times100=4\times4=16\)
b.\(0.5\times72+\frac{3}{6}\times28=0.5\times72+0.5\times28=0.5\times\left(72+28\right)=0.5\times100=50\)
a) 4/25 × 72 + 4/25 × 28
= 4/25 × (72+28)
= 4/25 × 100
= 16/100 × 100
= 16
b) 0.5 × 72 + 3/6 × 28
= 5/10 × 72 + 3/6 × 28
= 1/2 × 72 + 1/2 × 28
= 1/2 × (72 + 28)
= 1/2 × 100
= 5/10 × 100
= 50
A=21/28-54/72:(21/28+48/72)
B=8/11.7/19+-12/19+7/19.-3/11
(72-152+28)-(-52+128+72)
\(\left(72-152+28\right)-\left(-52+128+72\right)\)
\(=\left(-52\right)-148=-200\)
bùi thiên lương giải chi tiết ra cho mik rồi mik k nha
đúng hai sai b, 28 : 4 = (28x2) : (4x2) c 72 : 12 = 72 :6 : 12 : 6 d, 72 : 12 =(72:6) : (12:6)
Tính hợp lý:
45-58+(-45)+(+58)-3
(-57)-(-12)+3-(-57)
-(-24)-(-30)+(-24)-30+8
-(-12)+(+19)-(+12)+8-19
47-(-53)+(-47)-(+53)
-(+28)+32-(-28)+(-34)
15-(+72)+(-15)+(+72)
20-(+46)+(-25)-(-46)
28-(-32)+(-28)-32+5
-75+(-49)+(+75)+49-12
Giúp e vs ạ
45-58+(-45)+(+58)-3=45-58-45+58-3=(45-45)+(58-58)-3=-3
(-57)-(-12)+3-(-57)=-57+12+3+57=(-57+57)+12+3=15
-(-24)-(-30)+(-24)-30+8=24+30-24-30+8=(24-24)+(30-30)+8=8
-(-12)+(+19)-(+12)+8-19=12+19-12+8-19=(12-12)+(19-19)+8=8
47-(-53)+(-47)-(+53)=47+53-47-53=(47-47)+(53-53)=0
-(+28)+32-(-28)+(-34)=-28+32+28-34=(-28+28)-(34-32)=-2
15-(+72)+(-15)+(+72)=15-72-15+72=(15-15)+(72-72)=0
20-(+46)+(-25)-(-46)=20-46-25+46=(20-25)+(46-46)=-5
28-(-32)+(-28)-32+5=28+32-28-32+5=(28-28)+(32-32)+5=5
-75+(-49)+(+75)+49-12=-75-49+75+49-12=(-75+75)+(49-49)-12=-12
\(...=45-58-45+58-3=-3\)
\(...=-57+12+3+57=15\)
\(...=24+30-24-30+8=8\)
\(...=12+19-12+8-19=8\)
\(...=47+53-47-53=0\)
\(...=-28+32+28-34=-2\)
\(...=15-72-15+72=0\)
\(...=20-46-25+46=-5\)
\(=...28+32-28-32+5=5\)
\(...=-75-49+75+49-12=-12\)
thực hiện phép tính
a) -65.(87-17)-87.(17-65)
b) 72.(28-49)+28.(-49-72)
c) 18-(-27)+63-(63+27)
A)
-65.(87-17)-87.(17-65)
=-65.87-(-65).17-87.17-87.(-65)
=-(-65).17-87.17
=65.17-87.17
=17.(65-87)
=17.(-22)
=-374
B)
72.(28-49)+28.(-49-72)
= 72.28-72.49+28.(-49)-28.72
= -72.49+28.(-49)
= 72.(-49)+28.(-49)
= (-49).(72+28)
= -49.100
=-4900
C)
18-(-27)+63-(63+27)
= 18+27+63-63-27
= 45+0-27
= 45+(-27)
=45-27
=18
KICK MÌNH NHÁ
Tính bằng cách thuện tiện:
72.(28-49)+28.(-49-72)
BẠN NÀO GHI CÁCH LÀM ĐẦY ĐỦ VÀ ĐÚNG NHẤT TỚ SẼ TÍCH CHO!
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