Respuesta :

If x+y=5, let y = 0 to find the x-intercept:  x=5.  The x-int. is at (5,0).
               Let x = 0 to find the y-int:  y=5.  The y-int is (0,5).

Plot (5,0) and (0,5), and then draw a straight line thru both points.

If x+y=5,  solving for y results in    y = -1x + 5
Comparing this to y = mx + b,      m=-1 and b= 5.  Again, the y-int. is (0,5).