Question

Cho tỉ lệ thức \(\frac{3x-y}{x+y}=\frac{3}{4}\) khi đó x/y=.........

Answer 1

Ta có:

3x-y/x+y = 3/4

4(3x-y)=3(x+y)

12x-4y = 3x+3y

9x = 7y

x/y = 7/9

Answer 2

\(\frac{3x-y}{x+y}=\frac{3}{4}\Leftrightarrow4\left(3x-y\right)=3\left(x+y\right)\Leftrightarrow12x-4y=3x+3y\Leftrightarrow12x-3x=4y+3y\Leftrightarrow9x=7y\)

=>x/y=7/9