Câu hỏi của Khúc Nhật Minh

Question

a,-4/x-1=x-1/-9

b, -1,75.x+(hỗn số 3 3/4)= -24

giúp mk vs ạ

thanks

Trần Tiến Pro ✓ · Accepted Answer

$\text{a) }\frac{-4}{x-1}=\frac{x-1}{-9}$

$\Leftrightarrow\left(x-1\right).\left(x-1\right)=\left(-4\right).\left(-9\right)$

$\Leftrightarrow\left(x-1\right)^2=36$

$\Leftrightarrow x-1=\sqrt{36}$

$\Leftrightarrow x-1=6$

$\Leftrightarrow x=7$

Câu trả lời:

$\text{a) }\frac{-4}{x-1}=\frac{x-1}{-9}$

$\Leftrightarrow\left(x-1\right).\left(x-1\right)=\left(-4\right).\left(-9\right)$

$\Leftrightarrow\left(x-1\right)^2=36$

$\Leftrightarrow x-1=\sqrt{36}$

$\Leftrightarrow x-1=6$

$\Leftrightarrow x=7$

Huỳnh Quang Sang · Answer

$a,\frac{-4}{x-1}=\frac{x-1}{-9}$

$\Rightarrow(x-1)(x-1)=(-4)\cdot(-9)$

$\Rightarrow(x-1)^2=36$

$\Rightarrow(x-1)^2=6^2$

$\Rightarrow x-1=\pm6$

$\Rightarrow\hept{\begin{cases}x-1=6\x-1=-6\end{cases}}\Rightarrow\hept{\begin{cases}x=7\x=-5\end{cases}}$

$b,-1,75\cdot x+3\frac{3}{4}=-24$

$\Rightarrow-1,75\cdot x+3,75=-24$

$\Rightarrow-1,75\cdot x=-24-3,75$

$\Rightarrow-1,75\cdot x=-27,75$

$\Rightarrow x=-27,75:(-1,75)$

Tính rồi tìm ra giá trị của x thôi :v