math
posted by sherri .
find thedomain and range of {(7,2), (6,4) (99,)(55)}=
evaluate f(x) +3x^24x3at f(x1)=
evaluate f(x)= 5x+8 atf(3)=
it will be well appreciated of what how and help with these math problems plz thank you

I answered the domain and range one above
f(x1) = 3(x1)^2  4 (x1)  3
= 3 x^2 6 x + 3  4x + 4  3
= 3 x^2  10 x +4
f(3) = 15 + 8 = 23