## Tìm x : 3/8. ( x – 2/3 ) – 2/9 . ( 3x – 1/2 ) = -7/36 0,6 – 160 % < x ≤ 11/3 : 22 / 18 với x ∈ Z 50%.x + 2/3 . x = x - 5 x + 9/5 - 3/10 . ( 5.x - 1/3

Question

Tìm x :
3/8. ( x – 2/3 ) – 2/9 . ( 3x – 1/2 ) = -7/36
0,6 – 160 % < x ≤ 11/3 : 22 / 18 với x ∈ Z 50%.x + 2/3 . x = x - 5 x + 9/5 - 3/10 . ( 5.x - 1/3 ) Giup mik với ạ

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3 years 2021-04-15T10:47:04+00:00 1 Answers 38 views 0

1. Đáp án:

Giải thích các bước giải:

a)

$\dfrac{3}{8}.(x – \dfrac{2}{3}) – \dfrac{2}{9}.(3x – \dfrac{1}{2})=\dfrac{-7}{36}$

$\dfrac{3}{8}x – \dfrac{1}{4} – \dfrac{2}{3}x – \dfrac{1}{9} = \dfrac{-7}{36}$

$\dfrac{3}{8}x – \dfrac{2}{3}x – \dfrac{1}{4} – \dfrac{1}{9} = \dfrac{-7}{36}$

$\dfrac{-7}{24}x – \dfrac{1}{4} – \dfrac{1}{9} = \dfrac{-7}{36}$

$\dfrac{-7}{24}x – \dfrac{1}{4} = \dfrac{-7}{36} + \dfrac{1}{9}$

$\dfrac{-7}{24}x – \dfrac{1}{4} = \dfrac{-7}{36} + \dfrac{4}{36}$

$\dfrac{-7}{24}x – \dfrac{1}{4} = \dfrac{-1}{12}$

$\dfrac{-7}{24}x = \dfrac{-1}{12} + \dfrac{1}{4}$

$\dfrac{-7}{24}x = \dfrac{-1}{12} + \dfrac{3}{12}$

$\dfrac{-7}{24}x = \dfrac{1}{6}$

$x = \dfrac{1}{6} : \dfrac{-7}{24}$

$x = \dfrac{1}{6} . \dfrac{-24}{7}$

$x = \dfrac{-4}{7}$

b)

$0,6 – 160$% $< x \leq \dfrac{11}{3} : \dfrac{22}{18}$

$\dfrac{3}{5} – \dfrac{8}{5} < x \leq \dfrac{11}{3} . \dfrac{9}{11}$

$-1 < x \leq 3$

$=> x ∈ {0, 1, 2, 3}$

c)

$50$%$x + \dfrac{2}{3}x = x – 5$

$\dfrac{1}{2}x + \dfrac{2}{3}x = x – 5$

$x(\dfrac{1}{2} + \dfrac{2}{3}) = x – 5$

$\dfrac{7}{6}x = x – 5$

$\dfrac{7}{6}x – x = 5$

$\dfrac{1}{6}x = 5$

$x=5 : \dfrac{1}{6}$

$x=30$

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