$temp = var - min_{var}$
$varscaled = weight \cdot\frac{temp}{(max_{var}-min_{var})}$

$10 \cdot \frac{1}{1}=10 \qquad 80 \cdot \frac{100}{200}= 40$
$10 \cdot \frac{0}{1}=0 \qquad 80 \cdot \frac{75}{200}=30$
$\qquad \qquad Diff=10$