Giải thích các bước giải:
\(\frac{a}{5}=\frac{b}{4}\)
\( \Leftrightarrow a=\frac{5b}{4}\)
\(\frac{b}{3} =\frac{c}{7}\)
\( \Leftrightarrow c=\frac{7b}{3}\)
\(\frac{b}{12} = \frac{d}{9}\)
\( \Leftrightarrow d=\frac{9b}{12}\)
Ta có:
\(a+b+c+d = 50\)\( \Leftrightarrow \) \(=\frac{5b}{4}+b+\frac{7b}{3}+\frac{9b}{12}=50\)
\( \Leftrightarrow b=\frac{75}{8}=9,375\)
Vậy
\(a=\frac{5.9,375}{4}=\frac{375}{32}\)
\(c=\frac{7.9,375}{3}=\frac{175}{8}\)
\(d=\frac{9.9,375}{12}=\frac{225}{32}\)
