Question 1180541


If {{{f(x)=a +bx}}}, what is {{{f(x+k)-f(x)}}}

first find {{{f(x+k)}}}

{{{f(x+k)=a +b(x+k)}}}

{{{f(x+k)=a +bx+bk}}}

now substitute in 

{{{f(x+k)-f(x)}}}

={{{a +bx+bk-(a +bx)}}}

={{{a +bx+bk-a -bx}}}...simplify

={{{bk}}}