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![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Tần số tương ứng của các giá trị 15, 17, 20, 24 là 3, 4, 2, 2
Chọn đáp án C.
![](https://rs.olm.vn/images/avt/0.png?1311)
1: \(=-145\cdot13+145\cdot57+57\cdot10-57\cdot145=-1315\)
2: \(=17\cdot15-17\cdot16+16\cdot17-16\cdot20=255-320=-65\)
3: \(=-38\cdot25+38\cdot4-25\cdot4+25\cdot38=13\cdot4=52\)
4: \(=23\cdot145-23\cdot17-145\cdot23+145\cdot6=479\)
5: \(=24\cdot15-24\cdot4+4\cdot24-4\cdot15=360-60=300\)
6: \(=199\left(15-17+17-5\right)=199\cdot10=1990\)
7: \(=-39\cdot5+39\cdot99+99\cdot10-99\cdot39=795\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\frac{17}{8}+\frac{28}{15}-\frac{8}{15}=\frac{17}{8}+\frac{4}{3}=\frac{83}{24}=3\frac{11}{24}\)
=> chọn a
![](https://rs.olm.vn/images/avt/0.png?1311)
Có 7 giá trị khác nhau của dấu hiệu là: 15, 16, 17, 18, 20, 22, 24
Chọn đáp án A.
![](https://rs.olm.vn/images/avt/0.png?1311)
1: \(=\dfrac{-5}{8}\cdot\dfrac{15}{4}=-\dfrac{75}{32}\)
2: \(=\dfrac{15}{17}\cdot\dfrac{25}{34}=\dfrac{375}{578}\)
3: \(=-12\cdot\dfrac{8}{3}=-4\cdot8=-32\)
4: \(=\dfrac{15}{14}\cdot\dfrac{20}{21}=\dfrac{50}{49}\)
5: \(=48\cdot\dfrac{24}{5}=230.4\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{15}{35}=\dfrac{15:5}{35:5}=\dfrac{3}{7}\)
\(\dfrac{24}{27}=\dfrac{24:3}{27:3}=\dfrac{8}{9}\)
\(\dfrac{17}{50}\) ( phân số dã tối giản )
\(\dfrac{15}{45}=\dfrac{15:3}{45:3}=\dfrac{5}{15}=\dfrac{5:5}{15:5}=\dfrac{1}{3}\)
\(\dfrac{99}{121}=\dfrac{99:11}{121:11}=\dfrac{9}{11}\)
`24/27` chưa được rút gọn nha:'>
\(\dfrac{24}{27}=\dfrac{24:3}{27:3}=\dfrac{8}{9}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 17*85+17*15-120
=17*(85+15)-120
=17*100-120
=1700-120
=1580
b)2.31.12+4.6.42+8.27.3
=24.31+24.42+24.27
=24.(31+42+27)
=24.100
=2400
c)24:{300:[375-(150+5*15)]}
=24:{300:[375-(150+75)]}
=24:[300:(375-225)]
=24:(300:150)
=24:2
=12
24x(-15)+(-15)x75-15
=-15x(24+75+1)
=-15x100
=-1500
#H
24x(-15)+(-15)x17-15
= -15 x (24+17-1)
= -15 x 40
= -600