Hi
Using the point-slope formula,to find slope of segment AC
A(0,5),
C(5,0) m = 5/-5 = -1
Using the standard slope-intercept form for an equation of a line y = mx + b
where m is the slope and b the y-intercept.
Equation of the Line including segment AC
y = -1x + b |Using ordered pair (0,5) to solve for b
5 = b
y= -x + 5 is the equation of the line including segment AC