5+3=20
5+4=24
5+5=28
5+6=32
vậy 5+8= ?
giúp mình nha
Giúp mình với nha
Bài 3. Tính hợp lý :
1) 84 + 245 + 16 2) 467 + 238 + 533 + 762 + 3465 3) 1 + 3 + 5 + 7 + … + 199 4) 8. 4. 34. 125. 25 5) (44. 52. 60) : (11. 13. 15) 6) 129. 172 – 73. 129 + 129 7) 78. 31 + 78. 24 + 22. 72 + 78. 17 | 8) 48. 55 + 52. 167 – 52. 112 9) 3. 25. 8 + 4. 6. 37 + 2. 38. 12 10) (2100 – 42) : 21 11) (64 + 27 + 28 + 29) : 32 12) 86. 8585 – 85. 8686 13) 1 - 2 + 3 - 4 + 5 - 6 + … + 101 14*) 1 + 2 – 3 – 4 + 5 + 6 – 7 – 8 +…+ 413 + 414 |
a,12/7*7/4+35/11:245/12
b,(3/4+8/3).(7/4-6/4):(6/5+12/5+1/5)
c,17/23.8/16.23/17.(-80).3/4
d,D= 1^2 / 1.2 . 2^2 / 2.3 . 3^2 / 3.4 . 4^2 / 4.5 . 5^2 / 5.6 . 6^2 / 6.7 . 7^2 . 7.8 . 8^2 / 8.9 . 9^2 / 9.10
nhanh cho mình nha
18 / 27 - 2 /6 ; 37 / 12 - 3 ; 5 - 14 / 3
10 /21 : 2 / 3 ; 3 / 5 : 3 / 4 ; 2 / 5 : 3 / 10 ; 3/8 : 9/4 ; 8/21 : 4 / 7 ; 8 / 5 : 15 /8
giúp mình nha mình sẽ cho 2 tích
bạn mình hỏi các bạn giải````````` giúp mình với nha :1+2+3+4+5+6+7+8+9+10-7-5:31+2+3+4+5+6+7+8+9+10-7-5.0=?
bài 1 : tính
1) 5/8 . 7/3 - 5/2 . 1/8 2) 21/10 . 3/4 - 21/10 - 3/4 3) -4 / 11 : -6/11 4) 2/7 . 14/3 -1 5) 4/7 : ( 1/5 . 4/7 ) 6) 12/7 . 7/4 + 35/11 : 245/121
7) ( 4/3 + 8/3 ) . ( 7/4 - 6/4 ) : ( 6/5 + 12/5 + 1/5 ) 8) ( 1/4 - 1/4 + 1/9 / 1/9 ) : ( 2/3 + 7/15 / 2/5 - 1/6 )
9) ( ( 2/193 - 3/389 ) . 193/17 + 33/34 ) : (( 7/1931 - 11 / 3862 ) . 1931 / 25 + 9/2 )
chú ý :
/ là phần nha , nếu có 2 cái (( là sẽ có ngoặc vuông nha ! nhanh nha mình đang gấp lắm
1) \(\frac{5}{8}.\frac{7}{3}-\frac{5}{2}.\frac{1}{8}=\frac{5}{8}.\frac{7}{3}-\frac{5}{8}.\frac{1}{2}=\frac{5}{8}\left(\frac{7}{3}-\frac{1}{2}\right)=\frac{5}{8}.\frac{11}{6}=\frac{55}{48}\)
2) \(\frac{21}{10}.\frac{3}{4}-\frac{21}{10}.\frac{3}{4}=\frac{21}{10}\left(\frac{3}{4}-\frac{3}{4}\right)=\frac{21}{10}.0=0\)
3) \(\frac{-4}{11}:\frac{-6}{11}=\frac{-4}{11}.\frac{-11}{6}=\frac{-4.\left(-11\right)}{11.6}=\frac{-4.\left(-1\right)}{1.6}=\frac{4}{6}=\frac{2}{3}\)
4)\(\frac{2}{7}.\frac{14}{3}-1=\frac{2.14}{7.3}-1=\frac{2.2}{1.3}-1=\frac{4}{3}-1=\frac{1}{3}\)
5)\(\frac{4}{7}:\left(\frac{1}{5}.\frac{4}{7}\right)=\frac{4}{7}:\frac{4}{35}=\frac{4}{7}.\frac{35}{4}=\frac{4.35}{7.4}=\frac{1.5}{1.1}=5\)
6) \(\frac{12}{7}.\frac{7}{4}+\frac{35}{11}:\frac{245}{121}=\frac{12.7}{7.4}+\frac{35}{11}.\frac{121}{245}=\frac{3.1}{1.1}+\frac{35}{11}.\frac{121}{245}=3+\frac{35}{11}.\frac{121}{245}=3+\frac{35.121}{11.245}=\frac{1.11}{1.7}=\frac{11}{7}\)
Giúp mình câu này rồi kết bạn nha:
7/8 + 3/4 =??
3/2 + 4/5 =??
6/7 x 5/6=??
5/6 : 8/9=??
7/8 + 3/4=13/8
3/2 + 4/5=23/10
6/7 * 5/6=5/7
5/6 : 8/9=15/16
\(\frac{7}{8}+\frac{3}{4}=\frac{28}{32}+\frac{24}{32}=\frac{52}{32}\)
\(\frac{3}{2}+\frac{4}{5}=\frac{15}{10}+\frac{8}{10}=\frac{23}{10}\)
\(\frac{6}{7}x\frac{5}{6}=\frac{30}{42}\)
\(\frac{5}{6}:\frac{8}{9}=\frac{5}{6}x\frac{9}{8}=\frac{45}{48}\)
\(\frac{7}{8}+\frac{3}{4}=\frac{13}{8}\)
\(\frac{3}{2}+\frac{4}{5}=\frac{23}{10}\)
\(\frac{6}{7}.\frac{5}{6}=\frac{5}{7}\)
\(\frac{5}{6}:\frac{8}{9}=\frac{15}{16}\)
câu 1:12: 6/5 + 4/7
CÂU 2: ( 5/6+ 3/4 ) : 19/8
CÂU 3 : ( 7/4- 5/3 ) : 3/2
GIÚP MÌNH NHA
\(\frac{12}{1}:\frac{6}{5}+\frac{4}{7}=\frac{60}{6}+\frac{7}{4}=\frac{10}{1}+\frac{7}{4}=\frac{40}{4}+\frac{7}{4}=\frac{47}{4}\)
\(\left(\frac{5}{6}+\frac{3}{4}\right)\cdot\frac{8}{19}=\frac{38}{24}\cdot\frac{18}{9}=\frac{38}{24}\cdot2=\frac{76}{24}=\frac{19}{6}\)
\(\left(\frac{7}{4}-\frac{5}{3}\right)\cdot\frac{2}{3}=\frac{1}{12}\cdot\frac{2}{3}=\frac{1}{13}\)
câu 1 : 62/35
câu 2 : 2/3
câu 3 : 1/18
nhớ tk m nhé
câu 1: 12:6/5+4/7=47/21
câu 2: (5/6+3/4):19/8=2/3
câu 3: (7/4-5/3):3/2=1/18
giúp mình câu này nha, nó ở trong sách luyện toán trang 12 nhé !
1) tính: a.8/5 - 5/6 x 3/4 b.7/8 + 5/6 : 2/3
2)tìm x: a)4/5 + x = 11/10 b)x - 3/4 = 5/7
1. a
\(\dfrac{8}{5}-\dfrac{5}{6}\cdot\dfrac{3}{4}\)
\(=\dfrac{8}{5}-\dfrac{5\cdot3}{3\cdot2\cdot4}\)
\(=\dfrac{8}{5}-\dfrac{5}{8}=\dfrac{39}{40}\)
1.b
\(=\dfrac{7}{8}+\dfrac{5}{6}\cdot\dfrac{3}{2}\)
\(=\dfrac{7}{8}+\dfrac{5\cdot3}{3\cdot2\cdot2}\)
\(=\dfrac{7}{8}+\dfrac{5}{4}=\dfrac{17}{8}\)
2.a
\(\dfrac{4}{5}+x=\dfrac{11}{10}\)
\(x=\dfrac{11}{10}-\dfrac{4}{5}=\dfrac{3}{10}\)
2.b
\(x-\dfrac{3}{4}=\dfrac{5}{7}\)
\(x=\dfrac{5}{7}+\dfrac{3}{4}=\dfrac{41}{28}\)
Tính các tổng:
a) S=1-2+3-4+...+205-2006
b) S=2-4+6-8+...+2004-2006
c) S=1+2-3-4+5+6-7-8+...+2002-2003-2004
Giúp mk nhé!Ai nhanh,ai đúng nhất mik sẽ tk và kb nha!
a)S=1-2+3-4+...+2005-2006
S=(1-2)+(3-4)+...+(2005-2006)
S=(-1)+(-1)+...+(-1) Dãy S có 2016 thì có 1008 cặp
S=(-1)x1008
S=-1008
b)Tương tự
c)S=1+2-3-4+5+6-7-8+...+2001+2002-2003-2004
S=(1+2-3-4)+(5+6-7-8)+...+(2001+2002-2003-2004)
S=(-4)+(-4)+...+(-4) Dãy S có 2004 số => có 1002
S=(-4)x1002
S=-4008
2/3 + 7/1 =
25/48 + 11/24 =
5/7 + 3/8
15/24 + 12/6
5/6 + 4/3
3/8 + 7/12 =
Giúp mình nhanh nha , mik đang cần gấp
2/3 + 7/1 = 2/3 + 7 = 2/3 + 21/3 = 23/3
25/48 + 11/24 = 25/48 + 22/48 = 47/48
5/7 + 3/8 = 40/56 + 21/56 = 61/56
15/24 + 12/6 = 5/8 + 2 = 5/8 + 16/8 = 21/8
5/6 + 4/3 = 5/6 + 8/6 = 13/6
3/8 + 7/12 = 9/24 + 14/24 = 23/24
= 23/3
= 47/48
=61/56
=21/8
=13/6
= 23/24