\(2\left|x-5\right|+3\left|5-x\right|=10\)

\(\Rightarrow2\left|x-5\right|+3\left|x-5\right|=10\)

\(\Rightarrow\left|x-5\right|.\left(2+3\right)=10\)

\(\Rightarrow\left|x-5\right|.5=10\)

\(\Rightarrow\left|x-5\right|=2\)

\(\Rightarrow\orbr{\begin{cases}x-5=2\\x-5=\left(-2\right)\end{cases}}\Rightarrow\orbr{\begin{cases}x=7\\x=3\end{cases}}\)

bn làm đúng rùi

5 đúng ko

Em chịu rồi anh Sơn ơi

đây là brismath.com đúng ko bạn

\(a,=\frac{4^2.4^3}{2^{10}}=4^5:2^{10}=\left(2^2\right)^5.:2^{10}=2^{10}:2^{20}=1\)

\(b,=\left(3^3\right)^5:3^8=3^{15}:3^8=3^7\)

\(c,=\left(3^3\right)^2.\left(5^2\right)^3=3^6.5^6=\left(3.6\right)^6=18^6\)

\(d,=\left(15^2\right)^4.9^4=225^4.9^4=\left(225.9\right)^4=2025^4\)

Mình biết câu b/c/d thôi thông cảm cho mình nha ko biết đúng hay sai chắc câu c sai nhá bạn

b) 2187

c) 0,04656

d) 390625

5⁴ . 20⁴/25⁵ . 45

TL: 

\(\frac{5^4.20^4}{25^5.4^5}=\frac{5^4.5^4.4^4}{(5^2)^5.4^5}=\frac{5^85^4}{5^{10}.4^5}=\frac{1}{25.4}=\frac{1}{100}\)

Sửa đề:

\(\frac{5^4.20^4}{25^5.4^5}\)

\(=\)\(\frac{5^4.5^4.4^4}{\left(5^2\right)^5.4^5}\)

\(=\)\(\frac{5^8.4^4}{5^{10}.4^5}\)

\(=\)\(\frac{1}{25.4}\)

\(=\)\(\frac{1}{100}\)

Vì | 2x - 0,5 | ≥ 0 ∀ x ∈ Z

\(\Rightarrow\left|2x-0,5\right|+\frac{1}{3}\ge\frac{1}{3}\)

Để \(\left|2x-0,5\right|+\frac{1}{3}\)nhận giá trị nhỏ nhất khi \(\left|2x-0,5\right|+\frac{1}{3}=\frac{1}{3}\)

<=> | 2x - 0,5 | = 0

<=> 2x - 0,5 = 0

<=> 2x = 0,5

<=> x = 0,25

`|2x-0,5| + 1/3`

Vì `|2x-0,5| >= 0`

`-> |2x-0,5| +1/3 >= 1/3`

Dấu "=" xảy ra khi : `<=> |2x-0,5|=0 <=> x=1/4`

Vậy GTNN của BT là `1/3 <=> x=1/4`

\(c,TH1:\frac{2}{3}x-\frac{4}{9}=0=>x=\frac{2}{3}\)

\(TH2:\frac{1}{2}+-\frac{3}{7}:x=0=>x=\frac{6}{7}\)

Vậy \(x\in\left\{\frac{2}{3};\frac{6}{7}\right\}\)

c) \(\left(\frac{2}{3}.x-\frac{4}{9}\right)\left(\frac{1}{2}+\frac{-3}{7}:x\right)=0\)

\(\Rightarrow\orbr{\begin{cases}\frac{2}{3}.x-\frac{4}{9}=0\\\frac{1}{2}+\frac{-3}{7}:x=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}\frac{2}{3}.x=\frac{4}{9}\\\frac{-3}{7}:x=-\frac{1}{2}\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{2}{3}\\x=\frac{6}{7}\end{cases}}\)

k mik

đúng

hi

Xét ∆ABC và ∆ADE : 
AB = AD(gt) 
Góc BAC = góc EAD (cùng phụ với gócCAD ) 
AC = AE (gt) 
=>∆ABC = ∆ADE (c - g - c) 
=> BC = DE 
=> AM = BC/2 = DE/2

k cho mk nha

chúc bn trung thu vui vẻ

HT

\(\frac{\frac{4}{115}-\frac{4}{5}-\frac{4}{6115}}{\frac{7}{115}-\frac{7}{5}-\frac{7}{6115}}+\frac{3}{7}\)

\(=\frac{4.\left(\frac{1}{115}-\frac{1}{5}-\frac{1}{6115}\right)}{7.\left(\frac{1}{115}-\frac{1}{5}-\frac{1}{6115}\right)}+\frac{3}{7}\)

\(=\frac{4}{7}+\frac{3}{7}=1\)

\(a)\)\(\frac{\frac{4}{115}-\frac{4}{5}-\frac{4}{6115}}{\frac{7}{115}-\frac{7}{5}-\frac{7}{6115}}+\frac{3}{7}\)

\(=\)\(\frac{4.\left(\frac{1}{115}-\frac{1}{5}-\frac{1}{6115}\right)}{7.\left(\frac{1}{115}-\frac{1}{5}-\frac{1}{6115}\right)}+\frac{3}{7}\)

\(=\)\(\frac{4}{7}+\frac{3}{7}\)

\(=\)\(1\)

a) \(-\left(\frac{13}{25}-\frac{4}{191}+\frac{2}{51}\right)+\left(-\frac{4}{191}+\frac{2}{51}+\frac{3}{5}\right)\)

\(=-\frac{13}{25}+\frac{4}{191}-\frac{2}{51}-\frac{4}{191}+\frac{2}{51}+\frac{3}{5}\)

\(=\left(-\frac{13}{25}+\frac{3}{5}\right)+\left(\frac{4}{191}-\frac{4}{191}\right)-\left(\frac{2}{51}+\frac{2}{51}\right)\)

\(=\frac{2}{25}+0-0=\frac{2}{25}\)

b) \(12\frac{3}{5}:\left(-\frac{5}{7}\right)+2\frac{2}{5}:\left(-\frac{5}{7}\right)\)

\(=\frac{63}{5}.\frac{-7}{5}+\frac{12}{5}.\frac{-7}{5}\)

\(=\left(\frac{63}{5}+\frac{12}{5}\right).\frac{-7}{5}\)

\(=15.\frac{-7}{5}=-21\)