Đáp án + Giải thích các bước giải:
Câu 1 :
`|x| = 1/3 - |5/4 - 7/5| => |x| = 1/3 - |25/20 - 28/20|` $\\$ `=> |x| = 1/3 - |-3/20|` $\\$ `=> |x| = 1/3 - 3/20 = 20/60 - 9/60 = 11/60` $\\$ `=>`\(\left[ \begin{array}{l}x=\frac{11}{60}\\x=\frac{-11}{60}\end{array} \right.\)
Vậy `x in {11/60;-11/60}`
Câu 2 :
`|x| = 3/2 + [-5/6 - (-11/12)] => |x| = 3/2 + (-5/6 + 11/12)` $\\$ `=> |x| = 3/2 + (-10/12 + 11/12) = 3/2+1/12=19/12` $\\$ `=>`\(\left[ \begin{array}{l}x=\frac{19}{12}\\x=\frac{-19}{12}\end{array} \right.\)
Vậy `\color{green}{x in{19/12;-19/12}`
Câu 3 : `|x - 3/4| = 1/5 + (1/7 - 1/14)` $\\$ `=> |x- 3/4| = 1/5 + (2/14 - 1/14) = 1/5 + 1/14` $\\$ `=> |x - 3/4| = 14/70 + 5/70 = 19/70` $\\$ `+) x - 3/4 = 19/70 => x = 19/70 + 3/4 = 143/140` $\\$ `+) x - 3/4 = -19/70 => x = -19/70 + 3/4 = 67/140`
Vậy `\color{green}{x in {143/140;67/140}`
