Question

Tìm y biết:

y-5 / 7-y = 2/-3

Các bn giúp mk vs

Mk tìm mãi ko ra kết quả

Đề thi violympic vòng 17 lớp 6 đó

Bn nào giải đk mk tik cho

Answer 1

Giải:

Ta có: \(\dfrac{y-5}{7-y}=\dfrac{2}{-3}\)

\(\Rightarrow\left(y-5\right).\left(-3\right)=2\left(7-y\right)\)

\(\Rightarrow-3y+15=14-2y\)

\(\Rightarrow-3y+2y=-15+14\)

\(\Rightarrow-1y=-1\)

Vậy y=1

Answer 2

Ta có:y-5/7-y=2/-3

=>(y-5).(-3)=(7-y).2

=>-3y+15=14-2y

=>-3y+2y=14-15

=>-y=-1

=>y=1

Answer 3

\(\dfrac{y-5}{7-y}\)= \(\dfrac{2}{-3}\)

\(\Leftrightarrow\) -3(y-5)= 2(7-y)

\(\Leftrightarrow\) -3y+15 = 14 - 2y

\(\Leftrightarrow\) -3y+2y = 14-15

\(\Leftrightarrow\)-y = -1

\(\Leftrightarrow\) y = 1

Answer 4

\(\dfrac{y-5}{7-y}=\dfrac{-2}{3}\)

\(\Rightarrow3\left(y-5\right)=-2\left(7-y\right)\)

\(\Rightarrow3y-15=7y-49\)

\(\Rightarrow4y=34\)\(\Rightarrow y=\dfrac{17}{2}\)