[tex]\frac{1}{3}\ cup\ of\ milk\ for\ 1\ drink\\
\frac{7}{9}\ cup\ of\ milk\ for\ x\drinks\\\\
making\ proportion:\\
\frac{1}{3}-1\\
\frac{7}{9}-x\\\\
cross\ multiplication\\\\
\frac{1}{3}x=\frac{7}{9}\ \ \ \ multiply\ by\ 3\\\\
x=\frac{7}{3}=2\frac{1}{3}\\\\
Antonio\ can\ make\ 2\ lattes.
[/tex]
