Answer:
The relationship between the circumference of a circle and its diameter represent a direct variation and the constant of proportionality is equal to the constant 
Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form 
where K is the constant of proportionality
In this problem we know that
The circumference of a circle is equal to

therefore
the relationship between the circumference of a circle and its diameter is a direct variation and the constant of proportionality is equal to the constant 
17. It would be about 155
The second and the fourth
Answer:
y = (-3/7)x + 2
Step-by-step explanation:
slope-intercept form is y = mx + b, where m = slope and b = y-intercept.
all you need to do is plug the values into the equation! :)
since your slope is (-3/7), plug that in for m.
y = mx + b ⇒ y = (-3/7)x + b
and since your y-intercept is 2, plug that in for b.
y = (-3/7)x + b ⇒ y = (-3/7)x + 2
therefore, the line's equation in slope-intercept form is y = (-3/7)x + 2.
<em>don't worry about the parentheses, i only put them in there to separate the 7 in -3/7 from x. i'm not good at putting equations in here on brainly lol i just wanted to make sure you didn't think that it was -3 over 7x.</em>
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i hope this helps! have a lovely day <3