Answer:
y + 2 = (-5/4)x - 11.25
Step-by-step explanation:
If the relationship f is linear then its graph is a line D of equation y = ax+b
(-9 ,-2)∈D ⇔ -2 = -9a + b (1)
(-5 , -7)∈D ⇔ -7 = -5a + b (2)
(2)-(1)⇒ -5 = 4a ⇒ a = -5/4
-2 = -9a + b ⇒ -2 = -9(-5/4) + b ⇒ 2 +45/4 = -b ⇒ b = -13.25
then
D : y = (-5/4)x - 13.25 ⇒ y + 2 = (-5/4)x - 11.25
since (-1,-12) and (3,-17) are points of D (easy to check)
then it’s a linear relationship
