Hãy luôn nhớ cảm ơn và vote 5*
nếu câu trả lời hữu ích nhé!
$\text{a) I = ($\dfrac{x + 2}{3x}$ + $\dfrac{2}{x + 1}$ - 3) : $\dfrac{2 - 4x}{x + 1}$ - $\dfrac{3x - x² + 1}{3x}$ Đkxđ: x $\neq$ 0; x $\neq$ -1; x $\neq$ $\dfrac{1}{2}$ }$
$\text{= $\dfrac{(x + 2)(x + 1) + 2 . 3x - 3 . 3x(x + 1)}{3x(x + 1)}$ . $\dfrac{x + 1}{2 - 4x}$ - $\dfrac{3x - x² + 1}{3x}$}$
$\text{= $\dfrac{x² + x + 2x + 2 + 6x - 9x² - 9x}{3x(x + 1)}$ . $\dfrac{x + 1}{2(1 - 2x)}$ - $\dfrac{3x - x² + 1}{3x}$}$
$\text{= $\dfrac{-8x² + 2}{3x(x + 1)}$ . $\dfrac{x + 1}{2(1 - 2x)}$ - $\dfrac{3x - x² + 1}{3x}$ }$
$\text{= $\dfrac{-2(4x² - 1)}{3x(x + 1)}$ . $\dfrac{x + 1}{2(1 - 2x)}$ - $\dfrac{3x - x² + 1}{3x}$}$
$\text{= $\dfrac{2(2x - 1)(2x + 1)}{3x(x + 1)}$ . $\dfrac{x + 1}{2(2x - 1)}$ - $\dfrac{3x - x² + 1}{3x}$ }$
$\text{= $\dfrac{2x + 1}{3x}$ - $\dfrac{3x - x² + 1}{3x}$ }$
$\text{= $\dfrac{2x + 1 - 3x + x² - 1}{3x}$ }$
$\text{= $\dfrac{x² - x}{3x}$ }$
$\text{= $\dfrac{x(x - 1)}{3x}$ }$
$\text{= $\dfrac{x - 1}{3}$ }$
$\text{b) Có: x = 2022 (t/m)}$
$\text{Thay x = 2022 vào biểu thức I ta được:}$
$\text{I = $\dfrac{2022 - 1}{3}$}$
$\text{= $\dfrac{2021}{3}$}$
$\text{Vậy I = $\dfrac{2021}{3}$ khi x = 2022}$
$\textit{Ha1zzz}$
Hãy giúp mọi người biết câu trả lời này thế nào?
Bảng tin
10
953
4
Sao x khác cả 1/2 đc vậy?
3034
50621
2777
Để 2 - 4x $\neq$ 0 ý bạn