Question

Bài 4 trên cùng

Đề 21 bài 4

Answer 1

\(\frac{x+2}{-18}=\frac{-8}{x+2}\)

<=> (x+2)² = 144

<=> \(\left[\begin{array}{nghiempt}\left(x+2\right)^2=12^2\\\left(x+2\right)^2=\left(-12\right)^2\end{array}\right.\)

<=> \(\left[\begin{array}{nghiempt}x+2=12\\x+2=-12\end{array}\right.\)

<=> \(\left[\begin{array}{nghiempt}x=10\\x=-14\end{array}\right.\)

Answer 2

\(\frac{x-1}{x-5}=\frac{6}{7}\)

\(\Leftrightarrow7\left(x-1\right)=6\left(x-5\right)\)

\(\Leftrightarrow7x-7=6x-30\)

\(\Leftrightarrow x=-23\)

Answer 3

\(\frac{x-1}{x-5}=\frac{6}{7}\)

\(\Rightarrow7\left(x-1\right)=6\left(x-5\right)\)

\(\Rightarrow7x-7=6x-30\)

\(\Rightarrow7x-6x=-30+7\)

\(\Rightarrow x=-23\)

Vậy \(x=-23\)

Answer 4

Sao kết quả khác nhau quá vậy ^^