Question 1007939

The following question I had is 
Is it a function? How would I know? 
What type of slope would it be? How would I know?
What is the y-intercept how could I find it using this type of question? 
F(x) = 3/7x - 320 
This is all for one math problem thank you so much for taking the time to help me
I have a test on this soon so please please help!
<pre>{{{f(x) = (3/7)x - 320}}}____{{{y = (3/7)x - 320}}}
1) Use the vertical line test. The vertical line used will intersect the line of the equation: {{{f(x) = (3/7)x - 320}}} at ONLY 1 point. 
   Thus, the  equation: {{{f(x) = (3/7)x - 320}}} represents a FUNCTION.
2) A linear equation with an x-coefficient that's < 0 (negative) will have a negative slope (sloping downwards), while a linear equation
   with an x-coefficient that's > 0 ((positive) will have a positive slope or one that slopes upward. In this case, the coefficient of x ({{{3/7}}})
   is > 0, or positive so the slope of the line of the equation: {{{f(x) = (3/7)x - 320}}} slopes upward.
c) The y-intercept is at the point on the y-axis where the graph of the line intersects the y-axis. To get this, substitute 0 for x and solve for y. 
   If the equation is in "y = mx + b" form, as this one is, then the y-intercept is simply "b." Looking at this equation, the y-intercept is: {{{highlight_green(- 320)}}}.