ua, x,y,z o dau vay ban
\(\frac{1}{3}-|\frac{5}{4}-2x|=\frac{1}{4}\)
\(\Leftrightarrow|\frac{5}{4}-2x|=\frac{1}{4}+\frac{1}{3}=\frac{7}{12}\)
\(\Leftrightarrow\orbr{\begin{cases}Th1:\frac{5}{4}-2x=\frac{7}{12}\\Th2:\frac{5}{4}-2x=-\frac{7}{12}\end{cases}}\)
\(\Leftrightarrow Th1:\frac{5}{4}-2x=\frac{7}{12}\) \(\Leftrightarrow Th2:\frac{5}{4}-2x=-\frac{7}{12}\)
\(\Leftrightarrow2x=\frac{7}{12}+\frac{5}{4}\) \(\Leftrightarrow2x=-\frac{7}{12}+\frac{5}{4}\)
\(\Leftrightarrow2x=\frac{11}{6}\) \(\Leftrightarrow2x=\frac{2}{3}\)
\(\Leftrightarrow x=\frac{11}{12}\) \(\Leftrightarrow x=\frac{1}{3}\)
P/s : Mình làm bừa ạ nếu kh đúng xin mọi người chỉ thêm ~~
a)\(\frac{1}{3}-|\frac{5}{4}-2x|=\frac{1}{4}\Rightarrow|\frac{5}{4}-2x|=\frac{1}{3}-\frac{1}{4}=\frac{1}{12}\)
\(|\frac{5}{4}-2x|=\frac{1}{12}\Rightarrow\orbr{\begin{cases}\frac{5}{4}-2x=\frac{1}{12}\\\frac{5}{4}-2x=\frac{-1}{12}\end{cases}}\Rightarrow\orbr{\begin{cases}2x=\frac{7}{6}\\2x=\frac{4}{3}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{7}{12}\\x=\frac{2}{3}\end{cases}}\)
b,c làm tương tự
d) vì \(|x+1|\ge0;\forall x;|x+2|\ge0;\forall x;|x+3|\ge0;\forall x\)
suy ra \(|x+1|+|x+2|+|x+3|\ge0;\forall x\)
suy ra \(4x\ge0;\forall x\Rightarrow x\ge0\)
Với \(x\ge0\)ta có x+1+x+2+x+3 = 4x
suy ra 3x+6=4x
suy ra x=6 ( thỏa mãn \(x\ge0\))
Vậy x=6