Question

\(\frac{x-3}{x+5}=\frac{5}{7}\) ( x khác -5)

 

Answer 1

\(\frac{x-3}{x+5}=\frac{5}{7}\)

7(x - 3) = 5(x + 5)

7x - 21 = 5x + 25

7x - 5x = 25 + 21

2x = 46

x = 46 : 2

x = 23

Answer 2

Ta có : \(\frac{x-3}{x+5}=\frac{5}{7}\left(x\ne-5\right)\)

\(\Leftrightarrow\left(x-3\right).7=\left(x+5\right).5\)

\(\Leftrightarrow7x-21=5x+25\)

\(\Leftrightarrow7x-5x=25+21\)

\(\Leftrightarrow2x=46\)

\(\Leftrightarrow x=23\)