Question

Tìm x,biết

a./1-9x/-10=0

b./3-14x/-13=0

c./1-4x/-7=0

d./7x-8/-10=0

Answer 1

\(a.\left|1-9x\right|-10=0\)

\(\Leftrightarrow\left|1-9x\right|=10\Leftrightarrow\left[{}\begin{matrix}1-9x=10\\1-9x=-10\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=\dfrac{11}{9}\end{matrix}\right.\)

\(b.\left|3-14x\right|-13=0\)

\(\Leftrightarrow\left|3-14x\right|=13\Leftrightarrow\left[{}\begin{matrix}3-14x=13\\3-14x=-13\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-5}{7}\\x=\dfrac{8}{7}\end{matrix}\right.\)

c,d tương tự

Answer 2

c: =>|4x-1|=7

=>4x-1=7 hoặc 4x-1=-7

=>4x=8 hoặc 4x=-6

=>x=-3/2 hoặc x=2

d: =>|7x-8|=10

=>7x-8=10 hoặc 7x-8=-10

=>7x=-2 hoặc 7x=18

=>x=18/7 hoặc x=-2/7