Question 941518

{{{f(x)=mx+b}}} 

average rate of change between any two points is the slope of a line {{{m}}}


so, {{{m=5}}}

then we have {{{f(x)=5x+b}}}


if {{{f(0)=0}}} means if {{{x=0}}} => {{{f(x)=y=0}}} and that means y-intercept is at origin and {{{b=0}}} 

{{{f(x)=5x+0}}}

{{{f(x)=5x}}} is your answer