The ODE is separable:

Integrating both sides gives

It's not necessary that either one represents a proportional
relationship. But if either one does, then the other one doesn't.
They can't both represent such a relationship.
The graph of a proportional relationship must go through
the origin. If one of a pair of parallel lines goes through
the origin, then the other one doesn't. (If two parallel lines
both went through the origin, then they would both be the
same line.)
Answer:
b. -3
Step-by-step explanation:
9(2x+1) < 9x-18
(distribute the 9)
18x+9 <9x-18
(subtract 9 from both sides)
18x<9x-27
(subtract 9x from both sides)
9x<-27
(divide both sides by 9)
x<-3
For number 12 the answer is 15.36
Answer:
Vertex: (-1/2, -25/4)
Focus: (-1/2, -6)
Axis of Symmetry: x=-1/2
Directrix: y=-13/2
Step-by-step explanation:
x = -2, -1, -1/2, 1, 2
y = -4, -6, -25/4, -4, 0