![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{-13}{8}+\dfrac{-5}{9}+\dfrac{26}{26}-\dfrac{13}{9}\)
= \(\left(\dfrac{-13}{8}+\dfrac{26}{16}\right)+\left(\dfrac{-5}{9}-\dfrac{13}{9}\right)\)
= \(\left(\dfrac{-26}{16}+\dfrac{26}{26}\right)+\left(\dfrac{-18}{9}\right)\)
= \(0+\left(-2\right)\)
= \(-2\)
\(\left(\dfrac{-13}{8}-\dfrac{26}{16}\right)+\left(\dfrac{-5}{9}-\dfrac{13}{9}\right)=\left(\dfrac{-13}{8}-\dfrac{13}{8}\right)+\dfrac{-18}{9}=0+\left(-2\right)=-2\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 6:
\(\Leftrightarrow6n+4⋮2n-1\)
\(\Leftrightarrow2n-1\in\left\{1;-1;7;-7\right\}\)
hay \(n\in\left\{1;0;4;-3\right\}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
428=22.107
422=2.211
115=5.23
180=22.32.5
160=25.5
190=2.5.9
250=2.53
350=2.52.7
324=22.34
364=22.7.13
270=2.33.5
290=2.5.29
120=23.3.5
150=2.3.52
160=25.5
\(428=2^2\cdot107\)
\(422=2\cdot211\)
\(115=5\cdot23\)
\(180=2^2\cdot3^2\cdot5\)
\(160=2^5\cdot5\)
\(190=2\cdot5\cdot19\)
\(250=2\cdot5^3\)
\(350=2\cdot5^2\cdot7\)
\(324=2^2\cdot3^4\)
\(364=2^2\cdot7\cdot13\)
\(270=3^3\cdot2\cdot5\)
\(290=2\cdot5\cdot29\)
\(120=2^3\cdot3\cdot5\)
\(150=5^2\cdot2\cdot3\)
\(160=2^5\cdot5\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) Ta có: \(\dfrac{x}{27}=\dfrac{-2}{3.6}\)
nên \(x=\dfrac{-2\cdot27}{3.6}=\dfrac{-54}{3.6}=-15\)
b) Ta có: \(-0.52:x=-9.36:16.38\)
\(\Leftrightarrow x=\dfrac{-0.52}{-9.36:16.38}\)
\(\Leftrightarrow x=\dfrac{0.52}{9.36:16.38}\)
\(\Leftrightarrow x=\dfrac{91}{100}\)
c) Ta có: \(\dfrac{x}{-15}=\dfrac{-60}{x}\)
\(\Leftrightarrow x^2=900\)
hay \(x\in\left\{30;-30\right\}\)
d) Ta có: \(0,25\cdot x:3=0,125\)
\(\Leftrightarrow0,25\cdot x=0,375\)
hay x=1,5
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(1,\\ a,\overline{x23y}⋮2;5\Rightarrow y=0\\ \overline{x230}⋮9\Rightarrow x+2+3+0⋮9\\ \Rightarrow x=3\\ \Rightarrow\overline{x23y}=3230\)
Bài 2:
a: UCLN(24;36)=12
b: Gọi x là số học sinh
Theo đề, ta có:
\(x\in\left\{36;72;108;144;180;216;252;288;324;360;396;432;...\right\}\)
hay \(x\in\left\{216;252;288;324;360;396\right\}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(A=\dfrac{28-7^{2021}+5+7^{2021}}{7^{2021}}=\dfrac{33}{7^{2021}}\)
B=49/7^2021
=>A<B
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left(3x-4\right)^3=5^2+4.5^2\)
\(\Leftrightarrow\left(3x-4\right)^3=5^2\left(1+4\right)\)
\(\Leftrightarrow\left(3x-4\right)^3=5^3\)
\(\Leftrightarrow3x-4=5\Leftrightarrow3x=9\Leftrightarrow x=3\)
Ta có: \(\left(3x-4\right)^3=5^2+4\cdot5^2\)
\(\Leftrightarrow3x-4=5\)
hay x=3
Cảm giác có gì đó sai sai.... Bạn xem thế nào.![undefined](https://hoc24.vn/images/discuss/1629724485_61239f45056c6.jpg)
Chọn B