49.(-23+2.x)=(-49).(-23+14)
Tinh : (-7^2 ).(-23+2x)=(-49).(-23+14)
( - 72 ) . ( - 23 + 2x ) = ( - 49 ) . ( - 23 + 14 )
( - 72 ) . ( - 23 + 2x ) = ( - 49 ) . ( - 9 )
( - 72 ) . ( - 23 + 2x ) = 441
- 49 . ( - 23 + 2x ) = 441
- 23 + 2x = 441 : ( - 49 )
- 23 + 2x = - 9
2x = - 9 - ( - 23 )
2x = 14
x = 14 : 2
x = 7
(-7^2)*(-23+2x)=(-49)*-(-23+14)
Trả lời:x=...
A=49 8/23 - (5 7/32 + 14 8/23
\(49\dfrac{8}{23}-\left(5\dfrac{7}{32}+14\dfrac{8}{23}\right)=49\dfrac{8}{23}-5\dfrac{7}{32}-14\dfrac{8}{23}=\left(49\dfrac{8}{23}-14\dfrac{8}{23}\right)-5\dfrac{7}{32}=35-5\dfrac{7}{32}=\dfrac{953}{32}\)
49 8/23-(5 7/32+14 8/23) =?
A = 49/8/23 - (5/7/32+14/8/23)
a) 57 x 23 + 23 x 44 - 23
B)1672-[49 + (13-7)3]
C)50 : {2.[52-(3 . 5 - 22 . 3)3]}
D) -2014 + ( -999) +14 + (-2001)
a/57x23+23x44-23
57x23+23x44-23x1
=23x(57+44-1)
=23x100
=2300
b
a) 57 . 23 + 23 . 44 - 23
= 57 . 23 + 23 . 44 - 23 . 1
= ( 57 + 44 - 1 ) . 23
= 100 . 23
= 2300
b) 1672 - [ 49 + ( 13 - 7 )3 ]
= 1672 - [ 49 + 63 ]
= 1672 - [ 49 + 216 ]
= 1672 - 265
= 1407
c) 50 : { 2 . [ 52 - ( 3 . 5 - 22 . 3 )3 ] }
= 50 : { 2 . [ 52 - ( 3 . 5 - 4 . 3 )3 ] }
= 50 : { 2 . [ 52 - ( 3 . 1 )3 ] }
= 50 : { 2 . [ 52 - 27 ] }
= 50 : { 2 . 25 }
= 50 : 50
= 1
d) -2014 + (-999) + 14 + (-2001)
= ( -2014 + 14 ) + [ (-999) + (-2001) ]
= (-2000) + (-3000)
= -5000
Học tốt nhé bạn !
Tính hợp lí nhất
1, 2155– (174 + 2155) + (-68 + 174) 2, -25 . 72 + 25 . 21 – 49 . 25 3, 35(14 –23) – 23(14–35) 4, 8154– (674 + 8154) + (–98 + 674) 5, – 25 . 21 + 25 . 72 + 49 . 25 6, 27(13 – 16) – 16(13 – 27)
|
7, –1911 – (1234 – 1911) 8, 156.72 + 28.156 9, 32.( -39) + 16.( –22) 10, –1945 – ( 567– 1945) 11, 184.33 + 67.184 12, 44.( –36) + 22.( –28)
|
1) \( 2155 – (174 + 2155) + (-68 + 174) = -68\) 2) \(-25 . 72 + 25 . 21 – 49 . 25=-2500\) 3) \(35.(14 –23) – 23.(14–35)=168\) 4) \(8154 – (674 + 8154) + (–98 + 674)=-98\) 5) \(25.21+25.72+49.25=2399\) 6) \(27.(13-16)-16.(13-27)=143\) 7) \(–1911 – (1234 – 1911) =-1234\) |
Tính hợp lí nhất
1. 2155- (174 + 2155) + (-68 + 174)
2. -25 * 72 + 25 * 21 - 49 * 25
3. 35* (14-23) - 23 * (14-35)
4. 8154 - (674 + 8154) + (-98 + 674)
5. -25 * 21 + 25 * 72 + 49 * 25
6. 27* (13 - 16) - 16* (13 - 27)
7.-1911 - ( 1234 - 1911)
8.156 * 72 + 28 *156
9. 32 * (-39) + 16 * (-22)
10. -1945 - ( 567 - 1945 )
11. 184 * 33 + 67 * 184
12. 44 * ( -36 ) + 22 * ( -28)
Mọi người giúp em với
1: Ta có: \(2155-\left(174+2155\right)+\left(-68+174\right)\)
\(=2155-174-2155-68+174\)
=-68
2) Ta có: \(-25\cdot72+25\cdot21-49\cdot25\)
\(=-25\cdot\left(72-21+49\right)\)
\(=-25\cdot100=-2500\)
Bài 1: Tính một cách hợp lý
1/ 2155 - (174 + 2155) + (-68 + 174)
2/ -25 . 72 + 25 . 21 - 49 . 25
3/ 35 (14 - 23) - 23 (14-45)
4/ 8154 - (674 + 8154) + (-98 + 674)
5/ - 25 . 21 + 25 . 72 + 49 . 25
1/ 2155-(174+2155)+(-68+174)
=2155-174-2155-68+174
=[2155+(-2155)]+[(-174)+174]+(-68)
=0+0+(-68)
=-68
2/ -25.72+25.21-49.25
=25.(-72)+25.21-49.25
=25.[(-72)+21+(-49)]
=25.(-100)
=-2500
3/ 35.(14-23)-23.(14-45)
=35.14-35.23-23.14-23.45
=(35.14-23.14)+(-35.23-23.45)
=(35.14-23.14)+(-35.23-45.23)
=14.(35-23)+23.(-35-45)
=14.12+23.(-80)
=168+(-1840)
=-1672
4/ 8154-(674+8154)+(-98+674)
=8154-674-8154-98+674
=[8154+(-8154)]+[(-674)+674]+(-98)
=0+0+(-98)
=-98
5/ -25.21+25.72+49.25
=-12.25+25.72+49.25
=25.(-12+72+49)
=25.109
=2725
Đúng thì chọn đúng cho mình nhé !
27(13-16)-16(13-27)