Answer:
If ƒ(x ) = 3x + 1, then ƒ(a + h ) - ƒ(a ) = 3h
Step-by-step explanation:
Given ƒ(x ) = 3x + 1, then to calculate ƒ(a + h ) - ƒ(a ), you need to replace "x" for (a + h) and a, respectively.
So...
f(a +h) = 3(a + h) + 1
and
f(a) = 3a + 1
Then
ƒ(a + h ) - ƒ(a ) = 3 (a + h) + 1 - [3a +1] = 3a + 3h + 1 - 3a - 1 = 3h.
So, ƒ(a + h ) - ƒ(a ) = 3h