Bài 2:Tìm x: c.|x-55%|=7/15 d.|3x-1|+2/3=1

Đáp án:

Giải thích các bước giải:

 c)

| x-55% | = $\dfrac{7}{15}$

| x – $\dfrac{11}{20}$ | = $\dfrac{7}{15}$

x – $\dfrac{11}{20}$ = ± $\dfrac{7}{15}$

\(\left[ \begin{array}{l}x-\dfrac{11}{20}=\dfrac{7}{5}\\x-\dfrac{11}{20}=\dfrac{-7}{5}\end{array} \right.\) 

\(\left[ \begin{array}{l}x=\dfrac{7}{5}+\dfrac{11}{20}\\x=\dfrac{-7}{5}+\dfrac{11}{20}\end{array}\right.\) 

\(\left[ \begin{array}{l}x=\dfrac{39}{20}\\x=\dfrac{-17}{20}\end{array} \right.\)