so domain is what numbers you can put in so for functions lets say f(x)=x+1 if you put in 3 for x then you would have f(3)=3+1 so just put in the values they give you and the function will give you something else so
f(x)=4x-1
f(-5)=4(-5)-1
f(-5)=-20-1
f(-5)=-21
the domain is (-5) and the range is (-21)