Question: the faster moving star in a binary is

title: Binary star
text: r 1 = a ⋅ m 2 m 1 + m 2 = a 1 + m 1 m 2 ( \ displaystyle r_ ( 1 ) = a \ cdot ( \ frac ( m_ ( 2 ) ) ( m_ ( 1 ) + m_ ( 2 ) ) ) = ( \ frac ( a ) ( 1 + ( \ frac ( m_ ( 1 ) ) ( m_ ( 2 ) ) ) ) ) )