Question

\(\frac{x+1}{2}=\frac{8}{x+1}tìmx\)

Answer 1

ta có \(x+1.x+1=8.2=16\)

           \(x+1.x+1=4^2\)

            \(x+1=4\)

             \(x=3\)

Answer 2

Theo đầu bài ta có:
\(\frac{x+1}{2}=\frac{8}{x+1}\)
\(\Rightarrow\left(x+1\right)\left(x+1\right)=2\cdot8\)
\(\Rightarrow\left(x+1\right)^2=16\)
\(\Rightarrow x+1=\sqrt{16}\)
\(\Rightarrow x=4-1\)
\(\Rightarrow x=3\)

Answer 3

\(\frac{x+1}{2}\)=\(\frac{8}{x+1}\)Từ đây suy ra : x = 8:2=4 ; Thử đúng