Answer:
[tex]f(a+h)-f(a)=2ah+h^2+5h[/tex]
Step-by-step explanation:
Given function is [tex]f\left(x\right)=x^2+5x[/tex].
Using that function, we need to determine the value of f(a+h)-f(a).
[tex]f\left(x\right)=x^2+5x[/tex]
[tex]f\left(a+h\right)=(a+h)^2+5(a+h)[/tex]
[tex]f\left(a+h\right)=a^2+2ah+h^2+5a+5h[/tex]
similarly
[tex]f\left(a\right)=a^2+5a/tex]
Then [tex]f(a+h)-f(a)=(a^2+2ah+h^2+5a+5h)-(a^2+5a)[/tex]
[tex]f(a+h)-f(a)=a^2+2ah+h^2+5a+5h-a^2-5a[/tex]
[tex]f(a+h)-f(a)=2ah+h^2+5h[/tex]
Hence final answer is [tex]f(a+h)-f(a)=2ah+h^2+5h[/tex].