Question

a/3=b/2;a/4=c/5 và a+b-c=10

Answer 1

\(\dfrac{a}{3}=\dfrac{b}{2}\Rightarrow\dfrac{a}{12}=\dfrac{b}{8}\left(1\right)\\\dfrac{a}{4}=\dfrac{c}{5}\Rightarrow\dfrac{a}{12}=\dfrac{c}{15}\left(2\right) \)

Từ `(1);(2)=>a/12=b/8=c/15`

Áp dụng t/c của DTSBN , ta đc :

\(\dfrac{a}{12}=\dfrac{b}{8}=\dfrac{c}{15}=\dfrac{a+b-c}{12+8-15}=\dfrac{10}{5}=2\\ \Rightarrow\left\{{}\begin{matrix}a=12\cdot2=24\\b=8\cdot2=16\\c=15\cdot2=30\end{matrix}\right.\)

Answer 2

a/3=b/2

=>a/12=b/8

a/4=c/5

=>a/12=c/15

=>a/12=b/8=c/15=(a+b-c)/(12+8-15)=10/5=2

=>a=24; b=16; c=30