tính nhanh
10.000 - 47 * 72 + 47 * 28
tính nhanh:
10000 - 47 x 72 - 47 x 28
10000 - 47 × 72 - 47 × 28
= 100 × 100 - 47 × (72 + 28)
= 100 × 100 - 47 × 100
= 100 × (100 - 47)
= 100 × 53 = 5300
Tính bằng cách thuận tiện nhất:
10000 – 47 x 72 – 47 x 28
` 10000 – 47 xx 72 – 47 xx 28 `
`=10000-47xx(72+28)`
`=10000-47xx100`
`=100xx100-47xx100`
`=100xx(100-47)`
`=100xx53`
`=5300`
`10 000 - 47 xx 72 - 47xx28`
`=10 000 - 47 xx(72+28)`
`=10 000 - 47xx100`
`=10 000 - 4700`
`=5300`
10000 – 47 x 72 + 47 x 28
=10000-(47x(72+28)
=10000-4700
=5300
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
Bài 5*: Tính nhanh:
10000 - 47 x 72 - 47 x 28 3457 - 27 x 48 - 48 x 73 + 6543
=
1000 - 47 . 72 - 47 .28
= 47 . ( 1000 - 72 -28 )
= 47 .0
=0
3457 - 27 . 48 - 48 .73 + 6543
=3457 - 48 . (27 + 73 ) + 6543
= 3457 - 4800 + 6543
= 5200
-72.|-47|-28.|+47|
-72 . 47 - 28 . 47 = 47 . (-72-28) = 47 . -100 = -4700
-72.|-47|-28.|+47|
= -72.47 - 28.47
= 47. (-72-28)
= 47 . (-100)
= -4700
-72 . |-47| - 28 . |+47|
= -72 . 47 - 28 . 47
= 47 . (-72 - 28)
= 47 . (-100)
= -4700
bài 7:tính nhanh
a (145 x 99+145)-(143 x 102-143) b,54 x 47 - 47 x 53 - 20 -27
c, 10000 - 47 x 72 - 47 x 28 d, 3457 - 27 x 48 - 48 x 73 + 6543
a) \(\left(145\times99+145\right)-\left(143\times102-143\right)\)
\(=\left[145\times\left(99+1\right)\right]-\left[143\times\left(102-1\right)\right]\)
\(=\left(145\times100\right)-\left(143\times101\right)\)
\(=14500-14443\)
\(=57\)
b) \(54\times47-47\times53-20-27\)
\(=47\times\left(54-53\right)-20-27\)
\(=47-20-27\)
\(=0\)
c) \(10000-47\times72-47\times28\)
\(=10000-47\times\left(72+28\right)\)
\(=10000-47\times100\)
\(=10000-4700\)
\(=5300\)
d) \(3457-27\times48-48\times73+6543\)
\(=\left(3457+6543\right)-48\times\left(27+73\right)\)
\(=10000-48\times100\)
\(=10000-4800\)
\(=5200\)
10000-47*72-47*28
\(10000-47\cdot72-47\cdot28\)
\(=10000-3384-1316\)
\(=6616-1316\)
\(=5300\)
10000 - 47 x 72 - 47 x 28
= 10000 - (47 x 72 + 47 x 28)
= 10000 - 47 x (72 + 28)
= 10000 - 47 x 100
= 10000 - 4700
= 5300
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
\(...=45-58-45+58-3=-3\)
\(...=-57+12+3+57=15\)
\(...=24+30-24-30+8=8\)
\(...=12+19-12+8-19=8\)
\(...=47+53-47-53=0\)
\(...=-28+32+28-34=-2\)
\(...=15-72-15+72=0\)
\(...=20-46-25+46=-5\)
\(=...28+32-28-32+5=5\)
\(...=-75-49+75+49-12=-12\)
Tính bằng cách thuận tiện nhất:
a/ 10000 – 47 x 72 – 47 x 28
b/ 40025 – 25000 : 125 : 8
40025 - 25000 : 125 : 8
=40025 - 25000 : [125 nhân 8]
=40025 - 25000 : 1000
=40025 - 25
= 40000
chúc bạn học tốt
40025-25000:125.8
=40025-25000:(125.8)
=40025-25000:1000
=40025-25
=40000