Question 761432
if given line
{{{x + 2y =8}}}..write it in slope-intercept form {{{y = mx+b}}} to find a slope {{{m[1]}}}

{{{2y =-x+8}}}

{{{y =-x/2+8/2}}}

{{{y =-(1/2)x+4}}}...so, the slope {{{m[1]=-(1/2)}}}

as you know,the line perpendicular has a {{{m[2]=-1/m[1]}}}

{{{m[2]=-1/m[1]}}}....plug in {{{m[1]=-(1/2)}}}

{{{m[2]=-1/(-1/2)}}}

{{{m[2]=1/(1/2)}}}

{{{m[2]=2/1}}}

{{{m[2]=2}}}

then, the line perpendicular to given line is {{{y =2x+4}}}


let's see it on a graph:

{{{ graph(600, 600, -10, 10, -10, 10, -(1/2)x+4, 2x+4) }}}