Question 1151404
if x-intercepts of are {{{3}}} and {{{5}}} means   roots {{{x[1]=3}}}, {{{x[2]=5}}}

using root product rule find equation of the line

{{{y=f(x)=(x-3)(x-5)}}}

{{{ graph( 600, 600, -5, 10, -10, 10, (x-3)(x-5)) }}}

then
{{{y= 9f(x)=9(x-3)(x-5)}}}

set {{{y=0}}}

{{{9(x-3)(x-5)=0}}}=>x-intercepts of are same {{{3}}} and {{{5}}} 

{{{ graph( 600, 600, -5, 10, -10, 10, 9(x-3)(x-5)) }}}