3/4 + 1/y = 7 dan 1/x + 2/y = 9

[tex]\frac{3}{4}+\frac{1}{y}=7 \\ \frac{1}{y}=7-\frac{3}{4} \\ \frac{1}{y}=\frac{25}{4} \\ y=\frac{4}{25} \\ \\ \frac{1}{x}+\frac{2}{y}=9 \\ \frac{1}{x}+2\times\frac{25}{4}=9 \\ \frac{1}{x}+\frac{25}{2}=9 \\ \frac{1}{x}=9-\frac{25}{2} \\ \frac{1}{x}=-\frac{7}{2} \\ x=-\frac{2}{7} \\ \\ x=-\frac{2}{7}$ dan $y=\frac{4}{25}[/tex]

Eliminasi:
[tex]\frac{3}{4}+\frac{1}{y}=7 \\ $Kalikan 2$ \\ \frac{3}{2}+\frac{2}{y}=14 \\ \frac{1}{x}+\frac{2}{y}=9 \\ $kurangi$ \\ \frac{3}{2}-\frac{1}{x}=14-9 \\ \frac{3}{2}-\frac{1}{x}=5 \\ \frac{1}{x}=\frac{3}{2}-5 \\ \frac{1}{x}=-\frac{7}{2} \\ x=-\frac{2}{7} \\ \\ \frac{1}{x}+\frac{2}{y}=9 \\ -\frac{7}{2}+\frac{2}{y}=9 \\ \frac{2}{y}=9+\frac{7}{2} \\ \frac{2}{y}=\frac{25}{2} \\ \frac{1}{y}=\frac{25}{4} \\ y=\frac{4}{25}[/tex]