Question

cho x:y:z=5:4:3 và 2x-3y+5z khác 0 tính giá trị A=\(\dfrac{2x+3y-5z}{2x-3y+5z}\)

Answer 1

\(\Rightarrow\dfrac{x}{5}=\dfrac{y}{4}=\dfrac{z}{3}=\dfrac{2x+3y-5z}{10+12-15}=\dfrac{2x-3y+5z}{10-12+15}\\ \Rightarrow A=\dfrac{10+12-15}{10-12+15}=\dfrac{7}{13}\)

Answer 2

A=7/13