B.) Hibiscus Street
The key thing to remember is the slope of the lines. The equation for a line in slope intercept form is
y = ax + b
where
a = slope
b = y intercept
So the equation for Oak Street is y = 2/3x - 7. So it's slope is 2/3. And any street that has the same slope will be given a tree name. And any street that's perpendicular will be given a flower name. You can determine is a line is perpendicular if it has a slope that's the negative reciprocal. So a street that's perpendicular to Oak street will have a slope of -3/2.
Now you've just been given the equation to a new street that's y = -3/2x - 2. Since the slope is -3/2 and Oak street has a slope of 2/3, the new street is perpendicular to Oak street. And given the naming scheme, that means that the new street will have the name of a flower. So let's look at the available street names and pick a flower.
A.) Weeping Willow Street
* Nope a Weeping Willow is a tree. So this name won't work.
B.) Hibiscus Street
* Yes. A Hibiscus is a flower, so this name is suitable.
C.) Oak Street
* Nope. Not only is this a tree instead of a flower, but there's already an Oak street. So bad choice.
D.) Panther Street
* Nope, this is an animal, not a flower. Bad choice.
