Question

a)Tìm các số a,b,c biết rằng 

b)Tìm hai số x,y biết:

giúp mik vs thanks

Answer 1

a) \(2a=3b=4c\)

\(\Rightarrow\dfrac{a}{6}=\dfrac{b}{4}=\dfrac{c}{3}\)

Áp dụng t/c dtsbn:

\(\dfrac{a}{6}=\dfrac{b}{4}=\dfrac{c}{3}=\dfrac{a-b+c}{6-4+3}=\dfrac{35}{5}=7\)

\(\Rightarrow\left\{{}\begin{matrix}a=7.6=42\\b=7.4=28\\c=7.3=21\end{matrix}\right.\)

b) \(21x=19y\Rightarrow\dfrac{x}{19}=\dfrac{y}{21}\)

Áp dụng t/c dtsbn:

\(\dfrac{x}{19}=\dfrac{y}{21}=\dfrac{2x}{38}=\dfrac{y-2x}{21-38}=\dfrac{-34}{-17}=2\)

\(\Rightarrow\left\{{}\begin{matrix}x=2.19=38\\y=2.21=42\end{matrix}\right.\)