tính nhanh
78 + 23 x 81 - 69
78 + 23 x ( 81 - 69 )
( 78 + 23 ) x 81 - 69
( 78 + 23 ) x ( 81 - 69 )
2023 x 14 + 2023 x 83 +97
78 x 31 + 78 x 24 + 78 x 17 + 78 x 22 x 72
371 x 69 + 371 x 14 + 629 x 83
91 x 51 + 49 x 163 - 49 x 72
3 x 12 x 17 + 4 x 9 x 81 + 2 x 6 x 6
42 x 17 + 58 x 83 x 42 x 83 + 42 x 83 + 58 x 17
tính bằng cách hợp lý nhất
`@` `\text {Ans}`
`\downarrow`
`2023 \times 14 + 2023 \times 83+97`
`= 2023 \times (14+83) + 97`
`= 2023 \times 97 + 97`
`= 196231 +97`
`= 196328`
`78 \times 31+78 \times 24+78 \times 17+78 \times 22 \times 72`
`= 78 \times (31+24+17+22 \times 72)`
`= 78 \times (31+24+17+1584)`
`= 78 \times 1656`
`= 129168`
`371 \times 69+371 \times 14+629 \times 83`
`= 371 \times (69+14) + 629 \times 83`
`= 371 \times 83 + 629 \times 83`
`= 83 \times (371+629)`
`= 83 \times 1000`
`= 83000`
`91 \times 51+49 \times 163-49 \times 72`
`= 91 \times 51 + 49 \times (163-72)`
`= 91 \times 51+49 \times 91`
`= 91 \times (51+49)`
`= 91 \times 100`
`= 9100`
`3 \times 12 \times 17 + 4 \times 9 \times 81 + 2 \times 6 \times 6`
`= 9 \times 4 \times 17 + 4 \times 9 \times 81 + 4 \times 9 \times 2`
`= 9 \times 4 \times (17+81+2)`
`= 36 \times 100`
`= 3600`
`42 \times 17 + 58 \times 83 \times 42 \times 83 + 42 \times 83 + 17`
`= 17 \times (42+58) + 42 \times 83 \times (58 \times 83 +1)`
`= 17 \times 100 + 3486 \times 4815`
`= 1700 + 16785090`
`= 16786790`
bài 1 : tính nhanh
a, 23 + 25 + 27 + 29 + 31 + 33 + 35
b, 4 . 36 . 25 . 50
c, 32 . 125 . 3
d, 36 . 19 + 36 . 81
e, 78 . 31 + 78 . 24 + 78 . 17 + 22 x 72
Ai làm nhanh mình tik, giải rõ giúp mình, mình cảm ơn
a) 23 + 25 + 27 + 29 + 31 + 33 + 35
= 23 + ( 25 + 35 ) + ( 27 + 33 ) + ( 29 + 31 )
= 23 + 60 + 60 + 60
= 23 + 60 x 3
= 23 + 180
= 203
b) 4 . 36 . 25 . 50
= 4 . 4 .9 . 25 . 25 . 2
= 4 . 25 . 4 . 25 . 9 . 2
= 100 . 100 . 9 . 2
= 10 000 . 18
= 180 000
c) 32 . 125 . 3
= 4 . 8 . 5 . 25 . 3
= 4 . 25 . 8 . 5 . 3
= 100 . 8 . 5 . 3
= 800 . 5 . 3
= 4000 . 3
= 12000
d, 36 . 19 + 36 . 81
= 36 . ( 19 + 81 )
= 36 . 100
= 3600
e, 78 . 31 + 78 . 24 + 78 . 17 + 22 x 72
= 78 . ( 31 + 24 + 17 ) + 22 x 72
= 78 . 72 + 22 . 72
= 72 . ( 78 + 22 )
= 72 . 100
= 7200
A)23+25+27+29+31+33+35
= (33+27)+(25+35)+(29+31)+23
=60+60+60+23
=60x3+23
=180+23
=203
B)4.36.25.50=(36.25).(4.50)
=(4.9.25).(2.2.50)
=(4.25).9 .(2.50).2
=100.9.100.2
=100.(9+2)
=100 .11
=1100
C)32.125.3=(4.8).125.3
=(125.8).(4.3)
=1000.12
=12000
D)36.19.36.81=36.(19+81)
= 36.100
=3600
E)78.31.+78.24+78.17+22x72=78.31+78.24+78.17+ (16+6).72
=78.31+78.24+78.17+78.16
=78.(31+24+17+16)
=78.88
=6864
Tính bằng cách thuận tiện nhất :
a ) 81 + 35 + 19
b ) 78 + 65 + 135 + 22
c ) 234 + 17716 + 23
d ) 85 + 99 + 1
a) \(\left(81+19\right)+35=135\)
b) \(\left(78+22\right)+\left(65+135\right)=100+200=300\)
c) \(\left(234+17716\right)+23=17950+23=17973\)
d) \(\left(99+1\right)+85=100+85=185\)
\(a,81+35+19=\left(81+19\right)+35=100+35=135\\ b,78+65+135+22=\left(78+22\right)+\left(65+135\right)=100+200=300\\ c,234+17716+23=\left(234+17716\right)+23=17950+23=17973\\ d,85+99+1=85+\left(99+1\right)=85+100=185\)
A) 81+ 19 +35
=100+35=135
B) 78+65+135+22
=78+22+65+135
100+200=300
mấy câu cx làm tương tự
Tính giá trị của biểu thức :
a ) 81 + 35 + 19 b ) 78 + 65 + 135 + 22
c ) 234 + 17716 + 23 d ) 85 + 99 + 1
a = (81+19)+35
=100+35=135
b = (78+22)+(65+135)
=100+200=300
c = (234+17716)+23
=17950+23=17973
d = (99+1)+85
=100+85=185
a) 81 + 35 + 19 = (81 + 19) + 35 = 100 + 35 = 135
b) 78 + 65 + 135 + 22 = (78 + 22) + (135 + 65) = 100 + 200 = 300
c) 234 + 17716 + 23 = 17950 + 23 = 17973
d) 85 + 99 + 1 = 85+ (99 + 1) = 85 + 100 = 185
\(a,=116+19=135\\ b,=143+135+22\\ =278+22=300\\ c,=17950+23=17973\\ d,=184+1=185\)
Điền dấu <, >, = thích hợp vào chỗ chấm:
34 ... 50 47 ... 45 55 ... 66
78...69 81...82 44...33
72...81 95...90 77...99
62...62 61...63 88...22
34 < 50 47 > 45 55 < 66
78 > 69 81< 82 44 > 33
72 < 81 95 > 90 77 < 99
62 = 62 61 < 63 88 > 22
Tính bằng cách thuận tiện nhất:
2/7 x 23/81 x 7/2 x 81/23
2 / 7 X 23 / 81 X 7/2 X 81/23
= ( 2/7 X 7/2 ) X ( 23 / 81 X 81 / 23 )
= 1 X 1
= 1
k mk vs nhé <3
\(\frac{2}{7}\times\frac{23}{81}\times\frac{7}{2}\times\frac{81}{23}=1\)
Các tử số và mẫu số giống nhau đều bị gạch bỏ.
Tính nhanh : 23 x 45 + 23 x 78 + 23 x 12 = ?
23 x 45 + 23 x 78 + 23 x 12
= 23 x ( 45 + 78 + 12)
= 23 x 135
=3105
= 23 x ( 45 + 78 + 12 )
= 23 x 135
= 3105
Ai tk mình thì mình tk lại
mik giúp bạn thì bạn giải giúp mik nha
23*45+23*78+23*12
=23*(45+78+12)
=23*135
=3105
Điền dấu >, <, = vào chỗ chấm
47 … 45 | 34 … 50 | 10 … 18 – 8 |
81 … 82 | 78 … 69 | 44 … 30 + 10 |
95 … 90 | 72 … 81 | 70 … 90 – 20 |
61 … 63 | 62 … 26 | 77 … 90 – 10 |
Lời giải chi tiết:
47 > 45 | 34 < 50 | 10 = 18 – 8 |
81 < 82 | 78 > 69 | 44 > 30 + 10 |
95 > 90 | 72 < 81 | 70 = 90 – 20 |
61 < 63 | 62 > 26 | 77 < 90 – 10 |
Tính hợp lí :
1) ( -81 ). 27 - 34. ( -77 )
2) ( -16 ). 32 - ( -4 )2. 18
3) ( -2 )4. 289 - 16. 189
4) 41. ( -18 ) + 41. ( -81 ) - 41
5) 17. ( -37 ) - 23. 37 - 46. ( -37 )
6) -48 + 48. ( -78 ) + 48. ( -21 )
7) 29. ( -13 ) + 27. ( -29 ) + ( -14 ). ( -29 )
1) $(-81)\cdot27-3^4\cdot(-77)$
$=(-81)\cdot27-81\cdot(-77)$
$=-81\cdot[27+(-77)]$
$=-81\cdot(27-77)$
$=-81\cdot(-50)$
$=81\cdot50$
$=4050$
2) $(-16)\cdot32-(-4)^2\cdot18$
$=(-16)\cdot32-16\cdot18$
$=-16\cdot(32+18)$
$=-16\cdot50$
$=-800$
3) $(-2)^4\cdot289-16\cdot189$
$=16\cdot289+16\cdot(-189)$
$=16\cdot[289+(-189)]$
$=16\cdot(289-189)$
$=16\cdot100$
$=1600$
4) $41\cdot(-18)+41\cdot(-81)-41$
$=1\cdot(-18)+41\cdot(-81)+41\cdot(-1)$
$=41\cdot[(-18)+(-81)+(-1)]$
$=41\cdot(-18-81-1)$
$=41\cdot(-99-1)$
$=41\cdot(-100)$
$=-4100$
5) $17\cdot(-37)-23\cdot37-46\cdot(-37)$
$=17\cdot(-37)+23\cdot(-37)-46\cdot(-37)$
$=-37\cdot(17+23-46)$
$=-37\cdot(40-46)$
$=-37\cdot(-6)$
$=37\cdot6$
$=222$
6) $-48+48\cdot(-78)+48\cdot(-21)$
$=48\cdot(-1)+48\cdot(-78)+48\cdot(-21)$
$=48\cdot[(-1)+(-78)+(-21)]$
$=48\cdot(-1-78-21)$
$=48\cdot(-79-21)$
$=48\cdot(-100)$
$=-4800$
7) $29\cdot(-13)+27\cdot(-29)+(-14)\cdot(-29)$
$=-29\cdot13+27\cdot(-29)+(-14)\cdot(-29)$
$=-29\cdot[13+27+(-14)]$
$=-29\cdot(40-14)$
$=-29\cdot26$
$=-754$
$\text{#}Toru$