Áp dụng t/c dãy tỉ số bằng nhau, ta có:
\(\dfrac{1+2y}{18}=\dfrac{1+4y}{24}=\dfrac{1+6y}{6x}=\dfrac{1+2y+1+4y+1+6y}{18+24+6x}=\dfrac{3+12y}{6\left(7+x\right)}=\dfrac{3\left(1+4y\right)}{2.3\left(7+x\right)}=\dfrac{1+4y}{2\left(7+x\right)}=\dfrac{1+4y}{24}\)=> 7 + x = 12
=> x = 5
Ta có :
\(\dfrac{1+2y}{18}=\dfrac{1+4y}{24}\)
\(\Leftrightarrow24\left(1+2y\right)=18\left(1+4y\right)\)
\(\Leftrightarrow24+48y=18+72y\)
\(\Leftrightarrow24-18=72y-48y\)
\(\Leftrightarrow24y=6\)
\(\Leftrightarrow y=\dfrac{1}{4}\)
Thay \(y=\dfrac{1}{4}\) ta có :
\(\dfrac{1+1}{24}=\dfrac{1+\dfrac{3}{2}}{6x}\)
\(=\dfrac{1}{12}=\dfrac{\dfrac{5}{2}}{6x}\)
\(\Leftrightarrow6x=\dfrac{5}{2}.12\)
\(\Leftrightarrow6x=30\)
\(\Leftrightarrow x=5\)
Vạy ...
