Question

$\frac{1}{2} = \frac{4}{ } \\\frac{ }{10} = \frac{12}{20} \\\frac{3}{6} = \frac{15}{ } \\\frac{9}{18} = \frac{3}{ }$

Answer 1

1/2=4/8
6/19=12/20
3/6=15/30
9/18=3/6