a)
Ta có \(\frac{1+2y}{18}=\frac{1+4y}{24}.\)
\(\Rightarrow\left(1+2y\right).24=\left(1+4y\right).18\)
\(\Rightarrow24+48y=18+72y\)
\(\Rightarrow24-18=72y-48y\)
\(\Rightarrow6=24y\)
\(\Rightarrow y=6:24\)
\(\Rightarrow y=\frac{1}{4}.\)
+ Thay \(y=\frac{1}{4}\) vào đề bài ta được:
\(\frac{1+2.\frac{1}{4}}{18}=\frac{1+4.\frac{1}{4}}{24}=\frac{1+6.\frac{1}{4}}{6x}\)
\(\Rightarrow\frac{1}{12}=\frac{\frac{5}{2}}{6x}\)
\(\Rightarrow12.\frac{5}{2}=6x\)
\(\Rightarrow30=6x\)
\(\Rightarrow x=30:6\)
\(\Rightarrow x=5\)
Vậy \(\left(x;y\right)=\left(5;\frac{1}{4}\right).\)
Chúc bạn học tốt!