\(x+4y\)-5\(z\) =?
Đề chua đủ em nhé
3\(x\) = 4y = 5z ⇒ \(x+4y-5z=x+3x-3x\) = 20 ⇒ \(x\) = 20
y = \(\dfrac{3}{4}\)\(x\) = 20 \(\times\) \(\dfrac{3}{4}\) = 15
z = \(\dfrac{3}{5}\)\(x\) = 20 \(\times\) \(\dfrac{3}{5}\) = 12
Vậy \(\left\{{}\begin{matrix}x=20\\y=15\\z=12\end{matrix}\right.\)