mở dấu trị tuyệt đối ra rồi tính như bình thường

a)|3x|-12,5=|-2,5|

3x-12,5=2,5

3x=2,5+12,5

3x=15

x=15:3

x=5

vậy x=5

a) \(2,5:4x=0,5:0,2\)

\(2,5:4x=\frac{5}{2}\)

\(4x=2,5:\frac{5}{2}\)

\(4x=1\)

\(x=\frac{1}{4}\)

Vậy \(x=\frac{1}{4}\)

b) \(\frac{1}{5}.x:3=\frac{2}{3}:0,25\)

\(\frac{1}{5}.x:3=\frac{8}{3}\)

\(\frac{1}{5}.x=\frac{8}{3}.3\)

\(\frac{1}{5}.x=8\)

\(x=8:\frac{1}{5}\)

\(x=40\)

Vậy \(x=40\)

a) \(\frac{2,5}{4x}=\frac{0,5}{0,2}\)

\(=>4x=\frac{0,2.2,5}{0,5}=1\)

\(=>x=\frac{1}{4}\)

b) \(\frac{1}{5}.\frac{x}{3}=\frac{2}{3}:0,25\)

\(=>\frac{x}{15}=\frac{4}{3}\)

\(=>x=\frac{4.15}{3}=20\)

a: \(\Leftrightarrow\left(x-\dfrac{2}{5}\right):\dfrac{3}{2}=-\dfrac{5}{4}+\dfrac{5}{2}=\dfrac{5}{4}\)

\(\Leftrightarrow x-\dfrac{2}{5}=\dfrac{5}{4}\cdot\dfrac{3}{2}=\dfrac{15}{8}\)

hay x=91/40

b: \(\Leftrightarrow\left(2.5x-3.6\right)=-1\cdot\dfrac{12}{7}=\dfrac{-12}{7}\)

=>2,5x=66/35

hay x=132/175

c: \(\Leftrightarrow\left(\dfrac{15}{4}-2x\right)=\dfrac{19}{9}:\dfrac{4}{3}=\dfrac{19}{9}\cdot\dfrac{3}{4}=\dfrac{19}{12}\)

=>2x=15/4-19/12=45/12-19/12=26/12

=>x=13/12

a/|x|-2,5=27,5

=>|x|=27,5+2,5=30

=>x=30 hoặc x=-30

b/\(\dfrac{3}{4}+\dfrac{2}{5}.x=\dfrac{29}{60}\)

=>\(\dfrac{2}{5}.x\)=\(\dfrac{29}{60}-\dfrac{3}{4}\)=\(\dfrac{-4}{15}\)

=>x=\(\dfrac{-4}{15}:\dfrac{2}{5}\)=\(\dfrac{-2}{3}\)

c/(x-1)\(^5\)=-32

=>x-1=-2 vì (-2)\(^5\)=-32

=>x=-2+1=-1

d/\(\dfrac{4}{5}.x+0,5=4.5\)

=>\(\dfrac{4}{5}.x+0,5=20\)

=>\(\dfrac{4}{5}.x=20-0,5=19,5\)

=>\(x=19,5:\dfrac{4}{5}\)=\(\dfrac{195}{8}\)