Question 1012421


{{{2x-4y=6 }}} 
{{{ax-8y=2}}}
---------------------in slope-intercept form will be
{{{ (2/4)x-6/4=y }}} 
{{{(a/8)-2/8=y}}}
------------------

 {{{(1/2)x-3/2=y }}} -> slope is {{{(1/2)}}}
{{{(a/8)-1/4=y}}} -> slope is {{{(a/8)}}}

if lines are parallel there is no solution; so, for lines to be parallel, slopes {{{must}}} be {{{equal}}}

{{{ (a/8)=(1/2)}}} ...solve for{{{ a}}}

{{{a=(1/2)8}}}

{{{a=4}}}

then we have

 {{{2x-4y=6 }}} 
{{{4x-8y=2}}}

this system have {{{no}}} solution

check:

*[invoke solve_by_graphing 2, -4, 6, 4, -8, 2]