Question

[Khúc Nhật Minh]

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

b, -1,75.x+(hỗn số 3 3/4)= -24

 giúp mk vs ạ

thanks

Answer 1

[Trần Tiến Pro ✓]

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

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

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

\(\Leftrightarrow x-1=\sqrt{36}\)

\(\Leftrightarrow x-1=6\)

\(\Leftrightarrow x=7\)

Answer 2

[Huỳnh Quang Sang]

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

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

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

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

\(\Rightarrow x-1=\pm6\)

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

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

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

\(\Rightarrow-1,75\cdot x=-24-3,75\)

\(\Rightarrow-1,75\cdot x=-27,75\)

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

 Tính rồi tìm ra giá trị của x thôi :v