Question

|x + 3/4| + 1/3 = 0

Answer 1

\(\left|x+\dfrac{3}{4}\right|+\dfrac{1}{3}=0\)

\(\left|x+\dfrac{3}{4}\right|=0-\dfrac{1}{3}\)

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

\(\Rightarrow\left[{}\begin{matrix}x+\dfrac{3}{4}=\dfrac{1}{3}\\x+\dfrac{3}{4}=-\dfrac{1}{3}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}-\dfrac{3}{3}\\x=-\dfrac{1}{3}-\dfrac{3}{4}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{5}{12}\\x=-\dfrac{13}{12}\end{matrix}\right.\)

Answer 2

|x+3/4|>=0

=>|x+3/4|+1/3>=1/3>0 với mọi x

=>PTVN