11-7 hay 11-x bạn

\(\left(7-x\right)^3+\left(11-7\right)^2=141\\ \left(7-x\right)^3+4^2=141\\ \left(7-x\right)^3+16=141\\ \left(7-x\right)^3=141-16=125=5^3\\ Nên:7-x=5\\ Vậy:x=7-5=2\)

(7-x)³+(11-7)²=141

(7-x)³+4²=141

(7-x)³+16=141

(7-x)³=141-16

(7-x)³=125

(7-x)³=5³

7-x=5

r đó tự làm =)))

2/7 : 3/5 + 5/7 x 5/3

= (2/7 + 5/7) : (3/5 x 5/3)

= 1 : 1

= 1

a: =>x-22=9

hay x=31

5/7x : 1/8 = 5/4

x            =  5/4 : 5/7

x             = 24

\(3\dfrac{2}{7}x:\dfrac{1}{8}=2\dfrac{3}{4}\\ \dfrac{23}{7}x:\dfrac{1}{8}=\dfrac{11}{4}\\ \dfrac{23}{7}x=\dfrac{11}{4}\times\dfrac{1}{8}\\ \dfrac{23}{7}x=\dfrac{11}{32}\\ x=\dfrac{11}{32}:\dfrac{23}{7}\\ x=\dfrac{77}{736}\)

a) 3(x + 5) + 5(x + 7) = 58

3x + 15 + 5x + 35 = 58

8x + 50 = 58

8x = 58 - 50

8x = 8

x = 8 : 8

x = 1

b) 3(x + 7) - 2(x + 3) = 16

3x + 21 - 2x - 6 = 16

x + 15 = 16

x = 16 - 15

x = 1

\(x\times\frac{4}{7}+\frac{1}{3}\times x=\frac{2}{3}\)

\(x\times\left(\frac{4}{7}+\frac{1}{3}\right)=\frac{2}{3}\)

\(x\times\frac{19}{21}=\frac{2}{3}\)

\(x=\frac{2}{3}:\frac{19}{21}\)

\(x=\frac{2}{3}\times\frac{21}{19}=\frac{14}{19}\)

cảm ơn bé sói nha

Trl:

\(3\left|x-1\right|-5=7\)

\(\Rightarrow3\left|x-1\right|=7+5\)

\(\Rightarrow3\left|x-1\right|=12\)

\(\Rightarrow\left|x-1\right|=12:3\)

\(\Rightarrow\left|x-1\right|=4\)

\(\Rightarrow\orbr{\begin{cases}x-1=4\\x-1=-4\end{cases}\Rightarrow}\orbr{\begin{cases}x=4+1\\x=-4+1\end{cases}\Rightarrow\orbr{\begin{cases}x=5\\x=-3\end{cases}}}\)

Vậy \(x\in\left\{5;-3\right\}\)

\(3\left|x-1\right|-5=7\)

\(\Leftrightarrow3\left|x-1\right|=2\)

\(\Leftrightarrow\left|x-1\right|=\frac{2}{3}\)

\(\Leftrightarrow\orbr{\begin{cases}x-1=\frac{2}{3}\\x-1=-\frac{2}{3}\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{5}{3}\\x=\frac{1}{3}\end{cases}}\)

Vậy....

Nhầm

\(3\left|x-1\right|-5=7\)

\(\Leftrightarrow3\left|x-1\right|=12\)

\(\Leftrightarrow\left|x-1\right|=4\)

\(\Leftrightarrow\orbr{\begin{cases}x-1=4\\x-1=-4\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=5\\x=-3\end{cases}}\)

Vậy...