Question

Số nguyên y thỏa mãn  là 

Answer 1

\(\frac{y+5}{7-y}=\frac{2}{-5}\Leftrightarrow-5.\left(y+5\right)=2.\left(7-y\right)\Rightarrow-5y-25=14-2y\Leftrightarrow-3y=39\Leftrightarrow y=-13\)

Answer 2

Ta co : \(\frac{y+5}{7-y}=\frac{2}{-5}\)

\(\Rightarrow-5.\left(y+5\right)=2.\left(7-y\right)\)

\(\Leftrightarrow-5y-25=14-2y\)

\(\Leftrightarrow-14-25=-2y+5y\)

\(\Leftrightarrow-39=3y\)

\(\Leftrightarrow y=-39:3\)

\(\Leftrightarrow y=-3\)

Vay y=-3