If f(x) = 3x + 1, then f(a + h) - f(a) =
replace x with a+h and af(a+h)-f(a)=3(a+h)+1-(3a+1)=3a+3h+1-3a-1=3hresult is 3h
f(a+h) = 3(a+h) + 1 = 3a + 3h + 1f(a) = 3a + 1f(a+h) - f(a) = 3a + 3h + 1 - 3a - 1 = 3hAnswer: 3h