Question

Tìm al b; c biết 3a-5b+7c=86 và (a+3)/5=(b-2)/3=(c-1)/7

Answer 1

\(\frac{a+3-3}{5-3}=\frac{b-2+2}{3+2}=\frac{c-1+1}{7+1}=\frac{a}{2}=\frac{b}{5}=\frac{c}{8}=\frac{3a}{6}=\frac{5b}{25}=\frac{7c}{56}=\frac{86}{37}\)

\(\Rightarrow\frac{a}{2}=\frac{86}{37}\Rightarrow a=\frac{172}{37};\frac{b}{5}=\frac{86}{37}\Rightarrow\frac{430}{37};\frac{c}{8}=\frac{86}{37}\Rightarrow\frac{688}{37}\)