20+45:5-15-5+11
-3/5+28/5.(43/56+5/24-21/63)
(7/20+11/45-15/22):11/20-26/45
Cach lam ro rang nhe
Tính bằng cách hợp lý:
a) (44*52*60) : (11*13*15)
b) (16*17-5) : (16*16+11)
c) (27*700-24*45*20) : (45-40+35-30+25-20+15-10+5)
d) 1+6+11+16+...+46+51
a) (44 x 52 x 60) : (11 x 13 x 15)
= (44 : 11) x ( 52 : 13) x (60 : 15)
= 4 x 4 x 4 = 64
d) 1 + 6 + 11 + 16 + ... + 46 + 51
Ta có : 1 + 6 + 11 + 16 + ... + 46 + 51 ( có 11 số )
= (51 + 1) x 11 : 2 = 286
a, Ta thấy 44:11=4 , 52;13=4 , 60:15=4, => 4*4*4=64
b,Ta có : 16*17-5=16*(16+1)-5=16*16+16-5=16*16+11 Ta thấy Cụm 1 = Cụm 2 => Đáp án =1
Tính giá trị biểu thức
A = ( 5/12 × 21/15 ) : 1/4
B= ( 2/7 : 5/4 ) × ( 5/8 : 2)
C= ( 11/15 × 35/44 ) × ( 1/7 × 4/13 )
D= ( 7/20 + 11/15 - 15/12 ) : ( 11/20 - 26/45 )
\(A=\left(\dfrac{5}{12}.\dfrac{21}{15}\right):\dfrac{1}{4}\)
\(=\dfrac{7}{12}:\dfrac{1}{4}\)
\(=\dfrac{28}{12}=\dfrac{7}{3}\)
\(B=\left(\dfrac{2}{7}:\dfrac{5}{4}\right).\left(\dfrac{5}{8}:2\right)\)
\(=\dfrac{8}{35}.\left(\dfrac{5}{8}:2\right)\)
\(=\dfrac{8}{35}.\dfrac{5}{16}\)
\(=\dfrac{1}{14}\)
\(C=\left(\dfrac{11}{15}.\dfrac{35}{44}\right).\left(\dfrac{1}{7}.\dfrac{4}{13}\right)\)
\(=\dfrac{7}{12}.\left(\dfrac{1}{7}.\dfrac{4}{13}\right)\)
\(=\dfrac{7}{12}.\left(\dfrac{1}{7}.\dfrac{4}{13}\right)\)
\(=\dfrac{7}{12}.\dfrac{4}{91}\)
\(=\dfrac{1}{39}\)
\(D=\left(\dfrac{7}{20}+\dfrac{11}{15}-\dfrac{15}{12}\right):\left(\dfrac{11}{20}-\dfrac{26}{45}\right)\)
\(=\left(\dfrac{13}{12}-\dfrac{15}{12}\right):\left(\dfrac{11}{20}-\dfrac{26}{45}\right)\)
\(=\dfrac{-1}{6}:\left(\dfrac{11}{20}-\dfrac{26}{45}\right)\)
\(=\dfrac{-1}{6}:\dfrac{-1}{36}\)
\(=6\)
bài 1
4/7+4
3+6/11
3-5/7
21/9-2
15/24+2
63/45-20/25
3/4-2/8
6/7-5/8
37/45-5/9
46/39-11/13
5/12+3/4+1/3
1/2+3/7+11/14
7/10-(1/5+1/4)
15/4-2/3-3/4
`4/7+4`
`=4/7+4/1`
`=4/7+28/7`
`=32/7`
__
`3+6/11`
`=33/11+6/11`
`=39/11`
__
`3-5/7`
`=3/1-5/7`
`=21/7-5/7`
`=16/7`
__
`21/9-2`
`=21/9-18/9`
`=3/9`
`=1/3`
__
`15/24+2`
`=15/24+48/24`
`=63/24`
`=21/16`
__
`63/45-20/25`
`=63/45-4/5`
`=63/45-36/45`
`=27/45`
`=9/15`
__
`3/4-2/8`
`=3/4-1/4`
`=2/4`
__
`6/7-5/8`
`=48/56-35/56`
`=13/56`
__
`37/45-5/9`
`=37/45-25/45`
`=12/45`
`=4/15`
__
`46/39-11/13`
`=46/39-33/39`
`=13/39`
`=1/2`
__
`5/12+3/4+1/3`
`=5/12+9/12+4/12`
`=14/12+4/12`
`=18/12`
`=3/2`
__
`1/2+3/7+11/14`
`=7/14+6/14+11/14`
`=13/14+11/14`
`=24/14`
`=12/7`
__
`7/10-(1/5+1/4)`
`=7/10-(4/20+5/20)`
`=7/10-9/20`
`=14/20-9/20`
`=5/20`
`=1/4`
__
`15/4-2/3-3/4`
`=(15/4-3/4)-2/3`
`=12/4-2/3`
`=3-2/3`
`=9/3-2/3`
`=7/3`
Câu 1: what time is it?
10:15: it’s a quarter past ten
1. 20:15 it’s a quarter past eight p.m
2. 07:40 it’s twenty to eight.
3. 14:50
4. 18:23
5. 06:17
6. 20:45
7. 11:00
8. 14:55
9. 21:46
10. 22:30
11. 12:15
12. 05:42
13. 16:23
14. 10:45
15. 17:08
các bạn ơi giúp mình giải bài này với!!!!!
10:15: it’s a quarter past ten
1. 20:15 it’s a quarter past eight p.m.
2. 07:40 it’s twenty to eight.
3. 14:50: it's fifty past two p.m.
4. 18:23: it's twenty-three past six p.m.
5. 06:17: it's seventeen past six
6. 20:45: it's a quarter to nine p.m.
7. 11:00: it's eleven o'clock
8. 14:55: it's fifty-five past two p.m. / five to three p.m
9. 21:46: it's forty-six past nine p.m.
10. 22:30: it's half past ten p.m.
11. 12:15: it's a quarter past twelve
12. 05:42: it's forty-two past five
13. 16:23: it's twenty-three past four p.m.
14. 10:45: it's ten forty-five
15. 17:08: it's eight past five p.m.
Minh Châu Tiến Đạt thân mến, với bài đọc thời gian này em chỉ cần lưu ý:
- Cách đọc 1: giờ trước, phút sau: số giờ + số phút (+ p.m. hoặc a.m. hoặc in the evening / in the morning)
- Cách đọc 2: phút trước, giờ sau:
Đối với phút thứ 1-30, chúng tôi sử dụng PAST sau phút. Ex: eight past ten (10h08p)
Đối với phút thứ 31-59, chúng ta sử dụng TO sau phút. Ex: eight to ten (9h52p)
✽ O'clock được sử dụng với giờ đúng, KHÔNG có phút. Ex: 10 o'clock (10:00) -
✽ 12:00 Đối với 12h, có bốn cách diễn đạt bằng tiếng Anh:
midday = noon / midnight / twelve o'clock
✽15 = a quarter (1/4 của 60 phút / 1 giờ = 15 phút)
✽ a.m. (am) được dùng cho buổi sáng và p.m. (pm) cho buổi chiều và đêm.
Phản hồi đến em.
so sanh 21^15 va 27^5
15^12 va 81^3.125^5
3^39 va 11^21
72^45-72^44 va 72^44-72^43
199^20 va 2003^15
a) \(21^{15}=21^{3.5}=\left(21^3\right)^5=9261^5\)
Vì \(9261>27\Rightarrow9261^5>27^5\Rightarrow21^{15}>27^5\)
b) \(15^{12}=\left(3.5\right)^{12}=3^{12}.5^{12}\)
\(81^3.125^5=\left(3^4\right)^3.\left(5^3\right)^5=3^{4.3}.5^{3.5}=3^{12}.5^{15}\)
Vì \(3^{12}=3^{12}\)mà \(5^{12}< 5^{15}\Rightarrow3^{12}.5^{12}< 3^{12}.5^{15}\Rightarrow15^{12}< 81^3.125^5\)
Bài 1: Thực hiện phép tính:
a, \(\left(\dfrac{7}{20}+\dfrac{11}{15}-\dfrac{15}{12}\right):\left(\dfrac{11}{20}-\dfrac{26}{45}\right)\)
b, \(\dfrac{5-\dfrac{5}{3}+\dfrac{5}{9}-\dfrac{5}{27}}{8-\dfrac{8}{3}+\dfrac{8}{9}-\dfrac{8}{27}}:\dfrac{15-\dfrac{15}{11}+\dfrac{15}{121}}{16-\dfrac{16}{11}+\dfrac{16}{121}}\)
c, \(\dfrac{\dfrac{1}{9}-\dfrac{5}{6}-4}{\dfrac{7}{12}-\dfrac{1}{36}-10}\)
\(a,\left(\dfrac{7}{20}+\dfrac{11}{15}-\dfrac{15}{12}\right):\left(\dfrac{11}{20}-\dfrac{26}{45}\right).\)
\(=\left(\dfrac{21}{60}+\dfrac{44}{60}-\dfrac{75}{60}\right):\left(\dfrac{99}{180}-\dfrac{104}{180}\right).\)
\(=\left(\dfrac{65}{60}-\dfrac{75}{60}\right):\left(-\dfrac{5}{180}\right).\)
\(=-\dfrac{10}{60}:\left(-\dfrac{5}{180}\right).\)
\(=-\dfrac{1}{6}:\left(-\dfrac{1}{36}\right).\)
\(=-\dfrac{1}{6}.\left(-36\right).\)
\(=\dfrac{-1.\left(-36\right)}{6}=\dfrac{36}{6}=6.\)
Vậy......
\(b,\dfrac{5-\dfrac{5}{3}+\dfrac{5}{9}-\dfrac{5}{27}}{8-\dfrac{8}{3}+\dfrac{8}{9}-\dfrac{8}{27}}:\dfrac{15-\dfrac{15}{11}+\dfrac{15}{121}}{16-\dfrac{16}{11}+\dfrac{16}{121}}.\)
\(=\dfrac{5\left(1-\dfrac{1}{3}+\dfrac{1}{9}-\dfrac{1}{27}\right)}{8\left(1-\dfrac{1}{3}+\dfrac{1}{9}-\dfrac{1}{27}\right)}:\dfrac{15\left(1-\dfrac{1}{11}+\dfrac{1}{121}\right)}{16\left(1-\dfrac{1}{11}+\dfrac{1}{121}\right)}.\)
\(=\dfrac{5}{8}:\dfrac{15}{16}.\)
\(=\dfrac{5}{8}.\dfrac{16}{15}=\dfrac{5.16}{8.15}=\dfrac{1.2}{1.3}=\dfrac{2}{3}.\)
Vậy......
c, (làm tương tự câu b).
~ Học tốt!!! ~
Tính hợp lí
a) \(\left(4\frac{5}{37}-3\frac{4}{5}+8\frac{15}{29}\right)-\left(3\frac{5}{37}-6\frac{14}{29}\right)\)
b) \(\left(\frac{7}{20}+\frac{11}{15}-\frac{15}{12}\right):\left(\frac{11}{20}-\frac{26}{45}\right)\)
a) chứng tỏ : abcabc chia hết cho 11
b) tính nhanh 9 * 15 * 21 *12 * 20 / 5 *6 * 45 *18 * 4
c) tìm x 1- ( 5 4/9 + x +7 7/18) : 15 3/4 = 0
a) chứng tỏ : abcabc chia hết cho 11
Ta có 123123:11=11193
Vậy abcabc chia hết cho 11
b)\(\frac{9\cdot15\cdot21\cdot12\cdot20}{5\cdot6\cdot45\cdot18\cdot4}=\frac{9\cdot3\cdot5\cdot3\cdot7\cdot2\cdot2\cdot3\cdot2\cdot2\cdot5}{5\cdot2\cdot3\cdot5\cdot3\cdot3\cdot2\cdot3\cdot3\cdot2\cdot2}\)\(=\frac{7\cdot5}{3}=\frac{35}{3}\)