Answer: 
Step-by-step explanation:
By definition, the perimeter of a rectangle is:

Where "l" is the lenght and "w" is the width.
If you solve for "l":

In this case, you know that the following expression represents the perimeter of the rectangle:

And the width of that rectanle is represented wih this expression:

Therefore, based on the explained above, you can conclude that the lenght of that rectangle is given by:

Finally, simplifying the expression, you get:

i dont know if i can explain it right, but its kinda just like matching numbers to an equation with other numbers
google videos can explain it better and show
hope this help :)
Answer:
y=2x-2
Step-by-step explanation:
Slope intercept form y= mx+b
y-4 = 2(x-3)
y-4= 2x-6
y-4+4= 2x-6+4
y= 2x-2