Question

Cho p/s \(\frac{8n-3}{2n+1}\)( n thuộc Z)

Tìm n để A= \(\frac{13}{5}\)

Answer 1

\(\frac{8n-3}{2n+1}=\frac{13}{5}\)

\(\Rightarrow\left(8n-3\right)\cdot5=\left(2n+1\right)\cdot13\)

\(\Rightarrow40n-15=26n+13\)

\(\Rightarrow40n-26n=13+15\)

\(\Rightarrow14n=28\)

\(\Rightarrow n=28\div2\)

\(\Rightarrow n=14\)

Answer 2

ta có : 8n-3/2n+1=13/5

          (8n-3).5=(2n+1).13

           40n-15=26n+13

           40n-26n=15+23

           14n=28

suy ra n=28:14=2

vậy n=2