a) -55+(-13)
b) 4+(-10)
a) -55+(-13)
b) 4+(-10)
a) -55 + (-13) = -68
b) 4 + ( - 10 ) = -6
chúc bạn học tốt
a)-55+(-13)=-68
b)4+(-10)=-6
a) -55 + ( -13 )
= -68
b) 4 + ( -10 )
= -6
C/m rằng : a,( 10^19+10^18+10^17 ) chia hết 55; b, ( 81 ^7 - 27^9 - 9^13) chia hết cho 15; c, ( 4^13 + 32^5 - 8^8 ) chia hết cho 5 cảm ơn mn
C/m rằng : a,( 10^19+10^18+10^17 ) chia hết 55; b, ( 81 ^7 - 27^9 - 9^13) chia hết cho 15; c, ( 4^13 + 32^5 - 8^8 ) chia hết cho 5 cảm ơn mn
C/m rằng : a,( 10^19+10^18+10^17 ) chia hết 55; b, ( 81 ^7 - 27^9 - 9^13) chia hết cho 15; c, ( 4^13 + 32^5 - 8^8 ) chia hết cho 5 cảm ơn mn
Tính hợp lí: | a) 5. 11. 18 + 9. 31. 10 + 4. 29. 45;b) 37. 39 + 78. 14 + 13. 85 + 52. 55. |
a: \(5\cdot11\cdot18+9\cdot31\cdot10+4\cdot29\cdot45\)
\(=11\cdot\left(5\cdot18\right)+31\cdot\left(9\cdot10\right)+29\cdot2\cdot\left(2\cdot45\right)\)
\(=90\left(11+31+29\cdot2\right)\)
\(=90\cdot100=9000\)
b: \(37\cdot39+78\cdot14+13\cdot85+52\cdot55\)
\(=37\cdot39+39\cdot2\cdot14+13\cdot85+13\cdot4\cdot55\)
\(=39\left(37+2\cdot14\right)+13\cdot\left(85+4\cdot55\right)\)
\(=39\cdot65+13\cdot305\)
\(=13\left(65\cdot3+305\right)=13\cdot500=6500\)
a)
5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45
=90.11+90.31+2.29.90=90.11+90.31+2.29.90
=90.(11+31+2.29)=90.(11+31+2.29)
=90.100=9000
b)
37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55
=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11
=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44
=39.65+65.(17+44)=39.65+65.(17+44)
=39.65+65.61=39.65+65.61
=65.(39+61)=65.(39+61)
=65.100=6500
a)
5.11.18+9.31.10+4.29.45
=90.11+90.31+2.29.90
=90.(11+31+2.29)
=90.100
=9000
b)
37.39+78.14+13.85+52.55
=37.39+39.2.14+13.5.17+13.4.5.11
=39.(37+2.14)+65.17+65.44
=39.65+65.(17+44)
=39.65+65.61
=65.(39+61)
=65.100
=6500
So Sánh :
a) 3/13+4/7/26+1/1/2và4/3+4/37+55/111
b) 15/26+10/17+8/21và2
a) 3/13+4/7/26+1/1/2 va 4/3+4/37+55/111
3/13+111/26+3/2
=6
* 4/3+4/37+55/111
=55/37 =1,486
=> a> b
Lik-e ung ho nha
Bài 1 rút gọn rồi so sánh các phân số số a,4/7 và 33/55 b, 12/13 và 1212/1313 c, 5/7 và 20/28 d, 11/10 và
Giải cho mình cho mình với sáng mai mình phải nộp bài này rồi
Tính hợp lí:
a) 5 . 11 . 18 + 9 . 31 . 10 + 4 . 29 . 45
b) 37 . 39 + 78 . 14 + 13 . 85 + 52 . 55
Mình cần gấp !
a)
5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45
=90.11+90.31+2.29.90=90.11+90.31+2.29.90
=90.(11+31+2.29)=90.(11+31+2.29)
=90.100=9000
b)
37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55
=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11
=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44
=39.65+65.(17+44)=39.65+65.(17+44)
=39.65+65.61=39.65+65.61
=65.(39+61)=65.(39+61)
=65.100=6500
a.(5.18).11+(9.10).31+2.2.29.45
=90.11+90.31+(2.45).2.29
=90.11+90.31+90.2.29
=90.(11+31+2.29)
=90.100
=9000
a)
5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45
=90.11+90.31+2.29.90=90.11+90.31+2.29.90
=90.(11+31+2.29)=90.(11+31+2.29)
=90.100=9000
b)
37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55
=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11
=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44
=39.65+65.(17+44)=39.65+65.(17+44)
=39.65+65.61=39.65+65.61
=65.(39+61)=65.(39+61)
=65.100=6500
- Tính
(1+4+7+10+13+...+55+58) -410
Đặt S= 1 + 4 + 7 + 10 + 13 + ... + 55 + 58
SSH = \(\frac{58-1}{3}+1=19+1=20.\)số hạng
Tổng S = 1/2 * (58 + 1) *20 = 590.
Vậy A = (1 + 4 + 7 + 10 + 13 + ... + 55 + 58) -410 = 590 - 410 = 180.
(1+4+7+10+13+...+55+58)-410
=(58.19:2)-410
=551-410
=141