X^4 + 8x^2 - 9
= (x^2 + 9)(x^2 - 1)
= (x^2 + 9)(x + 1)(x - 1) Answer
Answer:
(-∞,∞) or {x | x ∈ R
Step-by-step explanation:
f(x) = ax + b
(0, -4):
f(0) = a•0 + b
f(0) = b ⇒ b = -4
(12, 0):
0 = a•12 + b
0 = 12a - 4
4 = 12a

The equation of the green line:

or: 