a) |x|=10/13 b) |x – 5/6 | = 1/2 c) |x+4/9|- 1/2 = 3/2

0 bình luận về “a) |x|=10/13 b) |x – 5/6 | = 1/2 c) |x+4/9|- 1/2 = 3/2”

1. Đáp án:

   `a)` `| x |` =`\frac{10}{13}`

   ⇒`x` =`\frac{10}{13}` hoặc `x` = `-\frac{10}{13}`

   `Vậy` `x` =`\frac{10}{13}` hoặc `x` = `-\frac{10}{13}`

   `b)` |`x` – `\frac{5}{6}`| = `\frac{1}{2}`

   ⇒ `Có` `2` `trường` `hợp `

   `TH1:` `x` – `\frac{5}{6}` = `\frac{1}{2}`

   `x` = `\frac{1}{2}`+`\frac{5}{6}`

   `x` = `\frac{4}{3}`

   `TH2:` `x` – `\frac{5}{6}` = `-\frac{1}{2}`

   `x` = `-\frac{1}{2}`+ `\frac{5}{6}`  

   `x` = `\frac{1}{3}`

   `Vậy` `x` =`\frac{4}{3}` hoặc `x` = `-\frac{1}{3}`

   c) |x + `\frac{4}{9}`| – `\frac{1}{2}` = `\frac{3}{2}`

   |x + `\frac{4}{9}`| = `\frac{3}{2}` + `\frac{1}{2}`

   |x + `\frac{4}{9}`| = `1`

   ⇒ `Có` `2` `trường` `hợp `:

   `TH1:` `x` + `\frac{4}{9}` = `1`

   `x` = `1` – `\frac{4}{9}`

   `x` = `\frac{5}{9}`

   `TH2:` `x` + `\frac{4}{9}` = `-1`

   `x` = `-1` – `\frac{4}{9}`

   `x` = `-\frac{13}{9}`

   `Vậy` `x` =`\frac{5}{9}` hoặc `x` = `-\frac{13}{9}`

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2. a) | x | = $\frac{10}{13}$ 

   => x = $\frac{10}{13}$ 

   b) | x – $\frac{5}{6}$ | = $\frac{1}{2}$ 

   => x – $\frac{5}{6}$  = $\frac{1}{2}$ => x = $\frac{1}{2}$ + $\frac{5}{6}$ => x = 1$\frac{1}{3}$

   => x – $\frac{5}{6}$  = – $\frac{1}{2}$ => x = – $\frac{1}{2}$ + $\frac{5}{6}$ = $\frac{1}{3}$

   c) | x + $\frac{4}{9}$ | – $\frac{1}{2}$ = $\frac{3}{2}$

   TH1: x + $\frac{4}{9}$ = $\frac{3}{2}$ + $\frac{1}{2}$ 

            x + $\frac{4}{9}$ = 2

            x = 2 – $\frac{4}{9}$

            x = 1$\frac{5}{9}$

   TH2: x + $\frac{4}{9}$ = – 2

            x = -2 – $\frac{4}{9}$

            x = -2$\frac{4}{9}$

   Chúc học tốt!!!

    

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