Question

[Võ Đăng Khoa]

tìm x biết :

a) 2 . |5x-3| - 2x = 14

b) |3x-2| - x = 7

c) |4x+3| - x = 15

d) |3x-2| + 5x = 4x -10

e) |3x-2| + 5x = 4x-10

f) |2x-6| + 5x = 9

g) |5x-3| - x = 7

Answer 1

[Despacito]

a) \(2.\left|5x-3\right|-2x=14\)

\(2\left|5x-3\right|=14+2x\)

\(\left|5x-3\right|=\frac{14+2x}{2}\)

\(\Rightarrow\orbr{\begin{cases}5x-3=\frac{-14-2x}{2}\\5x-3=\frac{14+2x}{2}\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}\left(5x-3\right).2=-14-2x\\\left(5x-3\right).2=14+2x\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}10x-6+2x=-14\\10x-6-2x=14\end{cases}\Rightarrow\orbr{\begin{cases}12x=-14+6\\8x=14+6\end{cases}}}\Rightarrow\orbr{\begin{cases}12x=-8\\8x=20\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{-2}{3}\\x=2,5\end{cases}}\)

vậy \(\orbr{\begin{cases}x=\frac{-2}{3}\\x=2,5\end{cases}}\)

Những câu sau tương tự nhé. 

Answer 2

[Võ Đăng Khoa]

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