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![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Phương pháp giải:
Trừ nhẩm các số rồi điền kết quả vào chỗ trống.
Lời giải chi tiết:
18 − 9 = 9 17 − 9 = 8
16 − 9 = 7 15 − 6 = 9
15 − 7 = 8 15 − 8 = 7
11 − 7 = 4 12 − 8 = 4
13 − 9 = 4 11 − 6 = 5
14 − 6 = 8 11 − 3 = 8
![](https://rs.olm.vn/images/avt/0.png?1311)
1) \(\left(+15\right)+\left(+17\right)=15+17=32\)
2) \(\left(-3\right)+\left(-7\right)=-3-7=-\left(3+7\right)=-10\)
3) \(\left(-25\right)+\left(+4\right)=-25+4=-\left(25-4\right)=-21\)
4) \(\left(-6\right)+\left(-54\right)=-6-54=-\left(6+54\right)=-60\)
5) \(\left(-15\right)+20=20-15=5\)
6) \(\left(-5\right)+8+7+5\)
\(=\left(-5+5\right)+\left(8+7\right)\)
\(=15\)
7) \(\left(-8\right)+\left(-11\right)+\left(-2\right)\)
\(=\left[\left(-8\right)+\left(-2\right)\right]+\left(-11\right)\)
\(=\left(-10\right)+\left(-11\right)\)
\(=-21\)
8) \(15+\left(-5\right)+\left(-14\right)+\left(-16\right)\)
\(=\left[15+\left(-5\right)\right]+\left[\left(-14\right)+\left(-16\right)\right]\)
\(=10+\left(-30\right)\)
\(=-20\)
9) \(\left(-20\right)+\left(-14\right)+3+\left(-86\right)\)
\(=\left[\left(-20\right)+3\right]+\left[\left(-14\right)+\left(-86\right)\right]\)
\(=\left(-17\right)+\left(-100\right)\)
\(=-117\)
10) \(\left(-136\right)+123+\left(-264\right)+\left(-83\right)+240\)
\(=\left[\left(-136\right)+\left(-264\right)\right]+\left[123+\left(-83\right)\right]+240\)
\(=\left(-400\right)+40+240\)
\(=\left(-360\right)+240\)
\(=-120\)
11) \(\left(-596\right)+2001+1999+\left(-404+189\right)\)
\(=\left(-596\right)+2001+1999-404+189\)
\(=\left[\left(-596\right)-404\right]+\left(2001+189\right)+1999\)
\(=\left(-1000\right)+2190+1999\)
\(=1190+1999\)
\(=3189\)
12) \(314+\left(-153\right)+64+121+\left(-247\right)+218\)
\(=\left(314+64+121\right)+\left[\left(-153\right)+\left(-247\right)\right]+218\)
\(=\left(378+121\right)+\left(-400\right)+218\)
\(=499-400+218\)
\(=99+218\)
\(=317\)
\(\text{#}Toru\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 8/15 + 1 = 23/15
b) 3/14 + 11/14 - 2/3 = 1- 2/3 = 1/3
c) 7/15 * (5/3+2/3) = 7/15 * 7/3= 49/45
d) 6/11 + 5/11 - 3/5 = 1 - 3/5 = 2/5
![](https://rs.olm.vn/images/avt/0.png?1311)
\(A=\frac{4}{3.7}+\frac{4}{7.11}+...+\frac{4}{107.111}\)
\(A=\frac{1}{3}-\frac{1}{7}+\frac{1}{7}-\frac{1}{11}+...+\frac{1}{107}-\frac{1}{111}\)
\(A=\frac{1}{3}-\frac{1}{111}\)
\(A=\frac{12}{37}\)
mà dài quá bạn ơi ban tách ra thành nhiều câu hỏi đi thế này trả lời lâu lắm
![](https://rs.olm.vn/images/avt/0.png?1311)
BÀI 1
a, \(5\times\frac{-7}{10}=\frac{-35}{10}=\frac{-7}{2}\)
b, \(\frac{4}{5}\times\frac{-7}{10}=\frac{-28}{50}=\frac{-14}{25}\)
c, \(\frac{4}{9}+\frac{4}{3}\times\frac{16}{4}=\frac{4}{9}+\frac{16}{3}=\frac{52}{9}\)
d, \(\frac{11}{22}-\frac{3}{9}\times\frac{14}{21}=\frac{11}{22}-\frac{2}{9}=\frac{55}{198}=\frac{5}{18}\)
BÀI 2
\(A=\frac{6}{13}\times\frac{5}{7}+\frac{6}{13}\times\frac{2}{7}+\frac{17}{13}\)
\(A=\frac{30}{91}+\frac{12}{91}+\frac{17}{13}\)
\(A=\frac{30}{91}+\frac{12}{91}+\frac{119}{91}\)
\(A=\frac{161}{91}=\frac{23}{13}\)
\(B=\frac{11}{15}\times\frac{4}{11}+\frac{11}{15}\times\frac{5}{11}+\frac{11}{15}\times\frac{2}{11}\)
\(B=\frac{4}{15}+\frac{1}{3}+\frac{2}{15}\)
\(B=\frac{11}{15}\)
\(C=\left(\frac{19}{64}-\frac{33}{22}+\frac{24}{51}\right)\times\left(\frac{1}{5}-\frac{1}{15}-\frac{2}{15}\right)\)
\(C=\frac{-797}{1088}\times0\)
\(C=0\)
\(D=\frac{8}{13}\times\frac{7}{12}+\frac{8}{13}\times\frac{5}{12}-\frac{1}{12}\)
\(D=\frac{14}{39}+\frac{10}{39}-\frac{1}{12}\)
\(D=\frac{83}{156}\)
bạn biết câu náy không (24 + 11) . {546 - [14 . (64 - 2^{3}3) : 2]} =
![](https://rs.olm.vn/images/avt/0.png?1311)
14/15 + 6/11 + 1/15 + 5/11 + 22/11
=(14/15 +1/15)+(6/11 + 5/11 + 22/11)
=1+3
=4
![](https://rs.olm.vn/images/avt/0.png?1311)
d=43/37d=43/37 × 23/15−43/3723/15−43/37 × 8/15+31/378/15+31/37
=43/37=43/37 x 23/15+43/3723/15+43/37 x (−8/15)+31/37(−8/15)+31/37
=43/37(23/15−8/15)+31/37=43/37(23/15−8/15)+31/37
=43/37.1+31/37=43/37.1+31/37
=2=2
E=−5/24E=−5/24 × 9/11−5/249/11−5/24 × 2/11+7/122/11+7/12
=−5/24(9/11+2/11)+7/12=−5/24(9/11+2/11)+7/12
=−5/24.1+7/12=−5/24.1+7/12
=3/8=3/8
a)3/7–−11/14−7/3×6/7a)3/7–−11/14−7/3×6/7
=3/7−−11/14−2=3/7−−11/14−2
=3/7+11/14−2=3/7+11/14−2
=−11/14=−11/14
b)6/5:3/2+−2/3×9/14b)6/5:3/2+−2/3×9/14
=4/5−3/7=4/5−3/7
=13/35
d=43/37d=43/37 × 23/15−43/3723/15−43/37 × 8/15+31/378/15+31/37
=43/37=43/37 x 23/15+43/3723/15+43/37 x (−8/15)+31/37(−8/15)+31/37
=43/37(23/15−8/15)+31/37=43/37(23/15−8/15)+31/37
=43/37.1+31/37=43/37.1+31/37
=2=2
E=−5/24E=−5/24 × 9/11−5/249/11−5/24 × 2/11+7/122/11+7/12
=−5/24(9/11+2/11)+7/12=−5/24(9/11+2/11)+7/12
=−5/24.1+7/12=−5/24.1+7/12
=3/8=3/8
a)3/7–−11/14−7/3×6/7a)3/7–−11/14−7/3×6/7
=3/7−−11/14−2=3/7−−11/14−2
=3/7+11/14−2=3/7+11/14−2
=−11/14=−11/14
b)6/5:3/2+−2/3×9/14b)6/5:3/2+−2/3×9/14
=4/5−3/7=4/5−3/7
=13/35
![](https://rs.olm.vn/images/avt/0.png?1311)
Lời giải chi tiết:
11 + 2 – 3 = 10 | 12 + 3 – 5 = 10 |
13 + 6 – 9 = 10 | 14 + 5 – 3 = 16 |
10 + 7 – 4 = 13 | 15 + 3 – 3 = 10 |
![](https://rs.olm.vn/images/avt/0.png?1311)
a; A = -1 + 3 - 5 + 7 - 9 + 11 - 13 + 15 - 17
A = (-1 + 11) + ( 3 - 13) + (-5 + 15) + (7 - 17) - 9
A = 10 - 10 + 10 - 10 - 9
A = (10 - 10) + (10 - 10) - 9
A = 0 + 0 - 9
A = -9
b; B = 1+2-3-4+5+6-7-8+9+10-11-12+13+14-15-16+17+18-19-20
B = (1+2-3-4) + (5+6-7-8)+(9+10-11-12)+(13+14-15-16)+(17+18-19-20)
B= -4+(-4)+(-4)+(-4)+(-4)
B= -4 . 5
B= -20
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 5 – 4 – 3 – 2 – 1 + 11 + 12 + 13 + 14 + 15
= (5 + 15) + (14 – 4) + (13 – 3) + (12 – 2) + (11 – 1)
= 20 + 10 + 10 + 10 + 10
= 60
b) 1 – 2 + 3 – 4 + 5 – 6 + 7 – 8 + 9 – 10 +11
= (1 + 3 + 5 + 7 + 9 + 11) – 2 – 4 – 8 – 10
= 36 – 24
= 12
\(\left(\frac{3}{7}\times\frac{11}{15}+\frac{3}{7}\times\frac{4}{15}\right)\) : \(\left(15+\frac{6}{11}-14\frac{6}{11}\right)\)
= \(\frac{3}{7}:1\)
= \(\frac{3}{7}\)
/HT\
\(\left(\frac{3}{7}\cdot\frac{11}{15}+\frac{3}{7}\cdot\frac{4}{15}\right):\left(15\cdot\frac{6}{11}-14\cdot\frac{6}{11}\right)\)
\(=\left[\frac{3}{7}\cdot\left(\frac{11}{15}+\frac{4}{15}\right)\right]:\left[\left(15-14\right)\cdot\frac{6}{11}\right]\)
\(=\left[\frac{3}{7}\cdot1\right]:\left[1\cdot\frac{6}{11}\right]\)
\(=\frac{3}{7}:\frac{6}{11}=\frac{3}{7}\cdot\frac{11}{6}\)
\(=\frac{11}{14}\)