Question

giúp mik vs

Answer 1

a: \(2,4-3x\cdot0,5=0,9\)

=>\(2.4x-1,5x=0,9\)

=>1,5x=2,4-0,9=1,5

=>x=1

b: \(\left|8,8x-50\right|:0,4=51\)

=>\(\left|8,8x-50\right|=51\cdot0,4=20,4\)

=>\(\left[{}\begin{matrix}8,8x-50=20,4\\8,8x-50=-20,4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}8,8x=70,4\\8,8x=29,6\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}x=8\\x=\dfrac{37}{11}\end{matrix}\right.\)

c: \(\left|\dfrac{3}{4}x-\dfrac{3}{4}\right|=\left|-\dfrac{3}{4}\right|\)

=>\(\dfrac{3}{4}\left|x-1\right|=\dfrac{3}{4}\)

=>|x-1|=1

=>\(\left[{}\begin{matrix}x-1=1\\x-1=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=0\end{matrix}\right.\)

d; \(\left(3x-4\right)^2=\left(-\dfrac{3}{4}\right)^2\)

=>\(\left(3x-4\right)^2=\dfrac{9}{16}\)

=>\(\left[{}\begin{matrix}3x-4=\dfrac{3}{4}\\3x-4=-\dfrac{3}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=\dfrac{19}{4}\\3x=\dfrac{13}{4}\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}x=\dfrac{19}{12}\\x=\dfrac{13}{12}\end{matrix}\right.\)

e: \(\left(\dfrac{1}{3}\right)^{2x-1}=3^5\)

=>\(3^{-2x+1}=3^5\)

=>-2x+1=5

=>-2x=4

=>x=-2

f: \(\left|5-3x\right|+\dfrac{2}{3}=\dfrac{1}{6}\)

=>\(\left|3x-5\right|=\dfrac{1}{6}-\dfrac{2}{3}=\dfrac{1}{6}-\dfrac{4}{6}=-\dfrac{3}{6}=-\dfrac{1}{2}< 0\)

=>Phương trình vô nghiệm