Question

Answer 1

a) Áp dụng t/c dtsbn ta có:

\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{x+y}{2+5}=-\dfrac{15}{5}=-3\)

\(\dfrac{x}{2}=-3\Rightarrow x=-6\\ \dfrac{y}{3}=-3\Rightarrow y=-9\)

b) \(3x=7y\Rightarrow\dfrac{x}{7}=\dfrac{y}{3}\)

Áp dụng t/c dtsbn ta có:

\(\dfrac{x}{7}=\dfrac{y}{3}=\dfrac{x-y}{7-3}=-\dfrac{16}{4}=-4\)

\(\dfrac{x}{7}=-4\Rightarrow x=-28\\ \dfrac{y}{3}=-4\Rightarrow y=-12\)