Remember that the slope intercept formula is:
y = mx + b
m is the slope
b is the y-intercept
so convert the equation -x + y = 5 into slope intercept form by adding x to both sides
(-x + x) + y = 5 + x
0 + y = 5 + x
y = 5 + x
To match the slope intercept formula switch the x and 5 around
y = x + 5
If lines are parallel then they have the same slope (m) but they have different b
This means that the slope of the line will be 1 (in front of the x is an invisible 1 which would be m)
This is what we have so far...
y = x + b
Now we must find b
To do that you must plug in the point the line goes through in the x and y of the equation.
(2, -5)
-5 = 1(2) + b
-5 = 2 + b
-7 = b
y = x + (-7)
y = x - 7
Hope this helped!
~Just a girl in love with Shawn Mendes