Question 1085666

the equation for a direct variation of a line:

{{{y=ax}}} 

if a line passes through ({{{2}}},{{{1}}}), we have 

{{{1=a*2}}} 

{{{1/2=a}}}

and your equation is: {{{y=(1/2)x}}} 


{{{drawing( 600, 600, -10, 10, -10, 10,
circle(2,1,.12),locate(2,1,p(2,1)),
 graph( 600, 600, -10, 10, -10, 10, (1/2)x)) }}}