Question 913972


Find a real number, {{{k}}}, such that the line {{{8x+ky-15=0}}} has y-intercept {{{9}}}. k=_____


{{{8x+ky-15=0}}} first write it in slope-intercept form

{{{ky=-8x+15}}} 

{{{y=-(8/k)x+15/k}}} ...slope {{{m=-(8/k)}}} and y-intercept {{{b=15/k}}}

if the line {{{8x+ky-15=0}}} has y-intercept {{{9}}}, than we know that y-intercept is at ({{{ 0 }}},{{{9}}})

{{{15/k=9}}} => {{{highlight(k=15/9)}}}


so, {{{8x+ky-15=0}}} will be {{{8x+(15/9)y-15=0}}}

in slope-intercept form

{{{y=-(8/(15/9))x+15/(15/9)}}}

{{{y=-(8*9/15)x+(15*9)/(15/9)}}}

{{{y=-(8*cross(9)3/cross(15)5)x+(cross(15)*9)/cross(15)}}}

{{{y=-(24/5)x+9}}}