Question 211932
First step is to solve for Y, or isolate Y on one side of the = sign.
Important rule to remember, anything you do to one side of the = you must do to the other when isolating a variable

5x-y=7   5x is a positive number, in order to move it from the left of the = and place it on the right, you must subtract it from both sides like this:

5x-5x-y=7-5x now siplify. 5x-5x is zero so the equation now looks like this
-y=7-5x

rearrange your terms like this 
-y=-5x+7 

Now we must move the negative in front of Y.  -y implies a negative one (-1) times y, in order to remove multiplication you must divide.  In this case you will divide -y by -1 and you will divide -5x+7 by -1.  When you divide by -1, it will change the signs for all.  So -y becomes y, and -5x+7 becomes 5x-7.  now your equation looks like this:
y=5x-7

We now have the equation in the form of y=mx+b

identify M: 5
identify b: -7

Whenever you have your equation in the form of y=mx+b, the coefficent (m) of x  is your slope on a graph, and b is your y intercept.  For this equation 5/1 (5 over 1) is your slope and -7 is your Y intercept.  Hope this helps!