b: \(\left(2x+1\right)^2=25\)

=>\(\left[{}\begin{matrix}2x+1=5\\2x+1=-5\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}2x=4\\2x=-6\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\)

c: \(\left(1-3x\right)^3=64\)

=>\(\left(1-3x\right)^3=4^3\)

=>1-3x=4

=>3x=1-4=-3

=>x=-3/3=-1

d: \(\left(4-x\right)^3=-27\)

=>\(\left(4-x\right)^3=\left(-3\right)^3\)

=>4-x=-3

=>x=4+3=7

e: \(x^2-5x=0\)

=>\(x\left(x-5\right)=0\)

=>\(\left[{}\begin{matrix}x=0\\x-5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=5\end{matrix}\right.\)

a: \(\Leftrightarrow x^2-x+4x-4+5⋮x-1\)

\(\Leftrightarrow x-1\in\left\{1;-1;5;-5\right\}\)

hay \(x\in\left\{2;0;6;-4\right\}\)

c: \(\Leftrightarrow4x-5=13k\left(k\in Z\right)\)

=>4k=13k+5

hay \(x=\dfrac{13k+5}{4}\)

`123-x=38`

`=> x= 123-38`

`=>x=85`

Vậy `x=85`

__

`(x+15) -7=33`

`=>x+15=33+7`

`=>x+16= 40`

`=>x=40-16`

`=>x=24`

Vậy `x=24`

__

`3^(x+3) -13=230`

`=> 3^(x+3) = 230+13`

`=>3^(x+3)=243`

`=> 3^(x+3)=3^5`

`=> x+3=5`

`=>x=5-3`

`=>x=2`

Vậy `x=2`

 Câu 20, 21 đk

Sorry bạn nha, mik chỉ làm câu a thôi

Đăng từng câu đio

,(8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)-33 đúng không bạn

a, 2,8

b, -4

\(a,0.25x\) - \(\frac{2}{3}x\) =\(1\frac{1}{6}\)

\(\Rightarrow x\cdot\left(0.25-\frac{2}{3}\right)=1\frac{1}{6}\)

\(\Rightarrow x\cdot\frac{-5}{12}=\frac{7}{6}\)

\(\Rightarrow x=\frac{7}{6}:\frac{-5}{12}\)

\(\Rightarrow x=\frac{-14}{5}=-2.8\)