Question

I am having a problem with solving this Given the function f described by f(x)=x+3, find each of the following:
f(0)
f(-13)
f(-12)
f(1)
f(4+8)
can you help me please?

Answer 1

first one f(0) = 0+3 = 3

last one f(4+8) = f(12) = 12+3 = 15